Code Inspections in PHP

This topic lists all PhpStorm code inspections available in PHP.

You can toggle specific inspections or change their severity level on the Editor | Inspections page of the IDE settings Ctrl+Alt+S.

Control flow

Inspection	Description	Default Severity
'foreach' variable overwrites already defined variable	Reports the keys and values in `foreach` loops that are assigned a non-primitive value before the `foreach` loop and are accessed after it. Such usages may unwillingly overwrite an already defined value and cause latent bugs.	Weak warning
'if' with common parts	Reports the `if` statements with duplicated common parts.	Weak warning
'never'-typed function returns a value	Reports the functions with the `never` return type hint that may return some value. Functions with such a return type are not expected to return any value. See noreturn type (php.net) for details.	Error
'switch' with common parts	Reports the 'switch' statements with duplicated common parts.	Weak warning
Array write access is not used	Reports the array write access expressions that are not used in code afterwards. The most common source of such problems is modifying an array passed via a parameter: if an array is passed by value, the change will not be visible outside the function.	Weak warning
Condition always evaluates to 'true/false'	Reports the conditions that are already covered by earlier conditions and thus have no effect as well as the variables that are always true (or always false) when reached.	Weak warning
Condition inside logical expression checked by subsequent condition	Reports the conditions inside logical binary expressions that are are covered by subsequent conditions and are therefore redundant.	Weak warning
Expression is always 'null'	Reports the variables in `return` statements that are always `null`.	Weak warning
Loop does not iterate	Reports the loop statements whose bodies will execute at most once. The inspection does not report `foreach` loops with a key or value used inside the loop body. Commonly, such loops are intended to perform an action only on their first iteration (for example, get the first element of an array).	Weak warning
Result of 'instanceof' is always 'true'	Reports the `instanceof` expressions whose argument is within the hierarchy of the checked variable. Such expressions will always evaluate to `true`.	Weak warning
Typed property might be uninitialized	Reports the attempts to read from an uninitialized typed property. Such attempts will result in `TypeError`. Typed properties should be initialized in any of the following ways: by a default value in the constructor by the `__get()` magic getter in-place, at the moment of usage See Uninitialized and Unset Properties (php.net) for details.	Warning
Unnecessary 'else' branch	Reports the `else` branches in `if` statements whose bodies always execute a terminating statement such as `return` or `throw`. Such branches are redundant and can be safely omitted.	No highlighting, only fix
Unreachable statement	Reports the statements that cannot be reached.	Warning
Write access to referenced array value without 'unset'	Reports the write access expressions on variables that are still referencing the array value previously used in a `foreach` statement. It is recommended to destroy such references by using `unset`. See foreach (php.net) and unset (php.net) for details.	Warning

Composer

Inspection	Description	Default Severity
Duplicate package entries in composer.json	Reports duplicate package entries in the `require` and `require-dev` sections of composer.json.	Weak warning
Extension is missing in composer.json	Reports the usages of classes, functions, and constants from the PHP extensions not specified in composer.json. If an extension is listed in the `require-dev` section of composer.json, the inspection reports the corresponding symbols' usages located outside of the folders marked as test roots.	Warning
Non-installed Composer packages	Reports the Composer packages that are required in composer.json but are not installed.	Weak warning
Quality tool inspection is disabled	Highlights the quality tools' entries in composer.json in case the corresponding code inspections are disabled.	Weak warning
Unresolved file references	Reports unresolved file references in composer.json.	Warning

Replaceable assignments

Inspection	Description	Default Severity
Assignment can be replaced with increment or decrement	Reports the assignments that can be replaced with incrementing (`++`) or decrementing (`--`) operations.	No highlighting, only fix
Assignment can be replaced with operator assignment	Reports the assignments that can be replaced with combined operator assignments (for example, `+=`).	No highlighting, only fix

Psalm

Inspection	Description	Default Severity
Function call is not compatible with 'callable' declaration	Reports the parameters in function calls whose types are not compatible with the ones defined via `Closure`.	Warning

PHPUnit

Inspection	Description	Default Severity
'assertTrue()' with incompatible argument type	Reports the PHPUnit `assertTrue()` calls whose arguments are of incompatible types. Since the `assertTrue()` method relies on strict types comparison with `true`, such assertions will always fail.	Warning
Assertion can be replaced with 'assertEmpty/assertNotEmpty'	Reports the `assertTrue`/`assertFalse` usages that can be replaced with `assertEmpty`/`assertNotEmpty` in PHPUnit tests. See assertEmpty (phpunit.readthedocs.io) for details.	Weak warning
Assertion can be replaced with 'fail'	Reports the `assertTrue()`/`assertFalse()` calls with the `false`/`true` arguments in PHPUnit tests. Such usages can be replaced with `fail()` calls to indicate that a test is expected to fail.	Weak warning
Covered function reference is provided without ‘::’	Reports the references to functions/methods in the `@covers` PHPDoc tags that are not prepended with the scope resolution operator (`::`).	Weak warning
Deprecated 'assertContains/assertNotContains' usage	Reports deprecated usages of the `assertContains` and `assertNotContains` functions with string `$needle` and `$ignoreCase` parameter. The string `$needle` and optional boolean `$ignoreCase` parameters of the `assertContains` and `assertNotContains` functions are deprecated and will be removed in PHPUnit 9. See Usage of the assertEquals function (phpunit.readthedocs.io) for details.	Weak warning
Deprecated 'assertEquals/assertNotEquals' usage	Reports deprecated usages of the `assertEquals` and `assertNotEquals` functions with `$delta`, `$maxDepth`, `$canonicalize`, and `$ignoreCase` parameters. The optional `$delta`, `$maxDepth`, `$canonicalize`, and `$ignoreCase` parameters of the `assertEquals` and `assertNotEquals` functions are deprecated and will be removed in PHPUnit 9. See Usage of the assertEquals function (phpunit.readthedocs.io) for details.	Weak warning
Deprecated 'assertFileEquals/assertStringEqualsFile' usage	Reports the deprecated usages of the `assertFileEquals`, `assertFileNotEquals`, `assertStringEqualsFile`, and `assertStringNotEqualsFile` functions with the `$canonicalize` and `$ignoreCase` parameters. The optional `$canonicalize` and `$ignoreCase` parameters of the `assertFileEquals` and `assertFileNotEquals` functions are deprecated and will be removed in PHPUnit 9. See Usage of the assertFileEquals function (phpunit.readthedocs.io) or Usage of the assertFileEquals function (phpunit.readthedocs.io) for details.	Weak warning
Deprecated @covers/@uses by access modifier annotation	Reports the `@covers` and `@uses` PHPUnit doc tags that are using `ClassName::<*>`. Such annotations won't be supported in PHPUnit 10 and later.	Weak warning
Deprecated exception handling via doc tags	Reports the usages of the following deprecated PHPUnit doc tags: `@expectedException` `@expectedExceptionMessage` `@expectedExceptionCode` `@expectedExceptionMessageRegExp`	Weak warning
Deprecated expectException usage	Reports deprecated usages of `expectException()`. Support for using the `expectException()` method with `\PHPUnit\Framework\Error\Deprecated`, `\PHPUnit\Framework\Error\Error`, `\PHPUnit\Framework\Error\Notice`, and `\PHPUnit\Framework\Error\Warning` is deprecated and will be removed in PHPUnit 10. Instead, the `expectDeprecation()`, `expectError()`, `expectNotice()`, and `expectWarning()` methods should be used. See Testing PHP Errors, Warnings, and Notices (phpunit.readthedocs.io) for details.	Weak warning
Method 'assertArrayHasKey/assertArrayNotHasKey' can be used instead	Reports the `assertTrue()` and `assertNotTrue()` methods calls that are provided with an `array_key_exists()` call as an argument. Such calls can be replaced with calls to the dedicated `assertArrayHasKey()` method. See assertArrayHasKey (phpunit.readthedocs.io) for details.	Weak warning
Method is deprecated in PHPUnit 10	Reports the calls to the PHPUnit assertion methods that are removed in PHPUnit 10.	Warning
Misordered PHPUnit equality assertion method arguments	Reports the calls to PHPUnit equality assertion methods (such as `assertEquals()`, `assertNotEquals()`, `assertSame()`, and so on) that have a non-literal as the expected result argument and a literal as the actual result argument. Such calls will behave fine for assertions that pass, but may produce confusing error reports if their expected and actual arguments differ. See assertEquals for details.	Weak warning
Missing target element for PHPUnit test	Reports the test classes and methods, for which no corresponding production classes or methods were found.	No highlighting, only fix
Undefined PHPUnit data provider	Reports the references to functions/methods in the `@dataProvider` PHPDoc tag that are not resolved. Note that when resolving `dataProvider`, PHPUnit doesn't take `use` statements into account.	Warning
Usage 'assertCount/assertSameSize' methods instead of assertEquals	Reports alternative usage of the `assertEquals` and `assertNotEquals` methods with `count` function as a parameter See Usage of the assertCount for details. See Usage of the assertSameSize for details.	Weak warning

PSR-12

Inspection	Description	Default Severity
Compound namespace depth is more than 2	Reports the usages of compound namespaces whose depth exceeds two levels. According to PSR-12, compound namespaces with a depth of more than two MUST NOT be used. See PSR-12: Extended Coding Style (php-fig.org) for details.	Disabled
Else if	Reports the usages of the `else if` constructs specified in two words. According to PSR-12, the keyword `elseif` SHOULD be used instead of `else if` so that all control keywords look like single words. See PSR-12: Extended Coding Style (php-fig.org) for details.	Disabled
Missing parameter list	Reports missing parameter lists in a classes' instantiations. According to the PSR-12 specification, when instantiating a new class, parentheses MUST always be present even when there are no arguments passed to the constructor. See PSR-12: Extended Coding Style (php-fig.org) for details.	Disabled
Missing visibility	Reports the properties, constants, and methods that are declared without visibility definition. According to PSR-12, visibility MUST be defined on: All properties, All constants if your project's PHP minimum version supports constant visibilities (PHP 7.1 or later), All methods. See PSR-12: Extended Coding Style (php-fig.org) for details.	Disabled
One-per-line trait uses	Reports the cases of several traits being imported via a single `use` statement. According to PSR-12, each individual trait imported into a class MUST be included one-per-line, and each inclusion MUST have its own `use` import statement. See PSR-12: Extended Coding Style (php-fig.org) for details.	Disabled
Order of modifiers	Reports visibility modifiers that are specified in the incorrect order. According to PSR-12, the correct order is as follows: When present, the `abstract` and `final` declarations MUST precede the visibility declaration. When present, the `static` declaration MUST come after the visibility declaration. See PSR-12: Extended Coding Style (php-fig.org) for details.	Disabled
Short form of type keywords	Reports usages of long form type keywords. According to PSR-12, short form of type keywords MUST be used, that is `bool` instead of `boolean`, `int` instead of `integer`, and so on. See Keywords and Types (php-fig.org) for details.	Disabled
Usage of var	Reports the usages of the `var` keyword for declaring class properties. According to PSR-12, the `var` keyword MUST NOT be used to declare a property. See PSR-12: Extended Coding Style (php-fig.org) for details.	Disabled

Attributes

Inspection	Description	Default Severity
'#[ArrayShape]' attribute can be added	Reports the methods and functions that are returning arrays with known non-trivial keys. Suggests specifying the shape of the returned array via the `#[ArrayShape]` attribute.	Weak warning
'#[Pure]' attribute can be added	Reports the functions that are non-trivially pure. Such functions have other functions calls in their body, but all such calls do not produce any side effects.	Weak warning
Array key does not match array shape	Reports the array keys that do not match the keys specified via the `#[ArrayShape]` attribute.	Weak warning
Attribute can be added to overriding member	Reports the methods' and parameters' attributes that can be propagated to overriding methods/parameters. See Attributes (php.net) for details.	Weak warning
Class cannot be used as attribute	Reports the attributes that are resolved to a class not annotated with `#[Attribute]`. See Attributes (php.net) for details.	Weak warning
Comment is parsed as attribute in PHP 8.0	Reports line comments starting with `#[`. In PHP 8.0 and later, such comments are parsed as attributes. See Attributes (php.net) for details.	Warning
Expected values should be used	Reports the values in assignment and comparison expressions that should be replaced with one of the expected values (that is, the values specified via the `#[ExpectedValues]` attribute). See Attributes (php.net) for details.	Weak warning
Immutable property written in invalid scope	Highlights write access references to properties, for which the write access scope declared via `#[Immutable]` is stricter than the reference scope.	Error
NoReturn attribute can be added	Reports function without `#[NoReturn]` that are always halting their execution by calling other exitPoint functions attribute.	Weak warning
Non-applicable attribute target declaration	Reports the attributes that do not have the appropriate `Attribute::TARGET_*` flag in their arguments declaration. See Attributes (php.net) for details.	Weak warning
Non-repeatable attribute	Reports repeated attributes without the `Attribute::IS_REPEATABLE` flag in their arguments declaration. See Attributes (php.net) for details.	Weak warning
Pure function may produce side effects	Reports the `#[Pure]` annotations used on functions that may produce side effects.	Weak warning
Redundant parentheses in attribute	Reports empty arguments lists in attributes. See Attributes (php.net) for details.	Weak warning

Code smell

Inspection	Description	Default Severity
'__toString' may throw an exception	Reports the usages of `__toString` that may throw an exception, which is not allowed for PHP language level lower than 7.4.	Warning
'array_push()' with single element	Reports the `array_push()` calls that are used to add a single element to an array. In such cases, it is recommended to use `$array[] =` instead, which adds no overhead of calling a function. See array_push (php.net) for details.	Weak warning
'array_search()' can be replaced with 'in_array()' call	Reports the `array_search()` calls that are only used for checking whether an element exists in array, that is, the expressions like `if (array_search($a, $b) === false) {}`. Such calls can be safely replaced with `in_array()` calls.	Weak warning
'continue' is targeting 'switch' statement	Reports the `continue` statements that are targeting `switch` statements. In PHP 7.3 and later, such usages are deprecated and will emit an `E_WARNING`, since they are most likely the result of a programming mistake. In PHP, such `continue` statements are equivalent to `break`, that is, they end the execution of the current `switch` structure. In other languages, such `continue` statements behave as `continue 2` in PHP, that is, they take the execution to a higher level control structure (for example, the next iteration of an outer loop). See continue (php.net), break (php.net), and switch (php.net) for details.	Weak warning
'func_get_arg()' call can be replaced with parameter access	Reports the `func_get_arg()` calls that can be replaced with direct parameter access.	Weak warning
'if' can be merged with subsequent condition	Reports the `if` statements that are followed by `elseif` or other `if` statements having the same bodies. Such statements can be merged together.	No highlighting, only fix
'in_array' can be replaced with comparison	Reports the `in_array()` calls that are provided with a single-element array as the `$haystack` argument. Such calls can be replaced with direct comparisons. See in_array (php.net) for details.	Weak warning
'match' expression has only default arm and should be simplified	Reports the `match` expressions only containing a `default` arm. Such expressions are redundant and should be simplified. See Match expression (php.net) for details.	Weak warning
'preg_match' can be replaced with 'str_contains'	Reports the `preg_match()` calls with `pattern` arguments that don't use any regexp facilities. Such calls can be replaced with `str_starts_with()` or `str_contains()` calls.	Weak warning
'switch' with single 'case'	Reports the `switch` statements that only contain a single `case` statement. Such `switch` statements can be converted into `if` statements.	Weak warning
Accessing static trait members	Reports the static member access expressions used on traits. Such direct access is deprecated starting from PHP 8.1. Instead, static members should be accessed on the class that uses the trait. See Deprecations for PHP 8.1: Accessing static members on traits (php.net) for details.	Weak warning
Argument of 'instanceof' should be only objects or strings	Reports arguments of 'instanceof' that are not objects or strings	Warning
Array access can be replaced with 'foreach' value	Reports the array access expressions inside `foreach` loops that can be replaced with a `foreach` value.	Weak warning
Array internal pointer reset is unnecessary	Reports the `reset($array)` calls on arrays whose internal pointer is already set on the first element. Such calls are redundant and can be safely removed. See reset (php.net) for details.	Weak warning
Array is always empty at the point of access	Reports the iterated/accessed arrays that are known to be empty at the point of access.	Weak warning
Array to string conversion	Reports array to string conversions, that is, the arrays that are provided in the contexts where a string is expected. Prior to PHP 8.0, this would lead to a `E_NOTICE` level error. In PHP 8.0, an `E-WARNING` is emitted.	Warning
Array used only with write access	Reports local arrays that are only updated, but never queried.	Weak warning
Boolean expression can be simplified	Reports the boolean expressions that contain the `true` or `false` literals and can be simplified.	Weak warning
Class constant referenced via child class	Reports the class constant references that target the constant from the parent class of the referenced class.	Weak warning
Concatenation to empty string can be merged with assignment	Reports the `.=` concatenation assignments performed right after assignment to an empty string literal. Such assignments can be merged together.	Weak warning
Condition can be replaced with 'min()'/'max()' call	Reports the conditions that perform manual min/max calculation instead of calling `min`/`max` functions.	Weak warning
Constant name defined with a leading slash	Reports the `define` constructs in which the constant's FQN starts with a leading slash. Such constants will not be correctly registered by PHP.	Warning
Duplicate branch in 'catch' statement	Reports `catch` statements with duplicated bodies.	Weak warning
Exception is immediately rethrown	Reports the `catch` statements that only rethrow a caught exception, which is located in a class hierarchy different from the subsequent exception types.	Weak warning
Foreach over array literal with single element	Reports the `foreach` statements that iterate over an array literal containing a single element.	Weak warning
Format function call with single argument	Reports the `sprintf()` and `vsprintf()` calls with a single argument. Such calls produce no effect and can be safely unwrapped, that is, replaced with the argument itself.	Weak warning
Idempotent operation in binary expression	Reports the binary expression operands that do not change the expression result (such as `+ 0` or `. ""`) and are therefore redundant.	Weak warning
Inconsistent return points	Reports inconsistencies in function/method exit points. The following types of inconsistencies are reported: The function/method contains the `return` statements both with and without arguments. The function/method may return a value or otherwise end its execution without returning anything. Technically these are not errors, but practically they usually indicate a programming mistake.	Warning
Logical expression has same operands	Reports the expressions that use the same operands, but should rather use different operands (for example, `$var == $var`). These include comparison, logical, null-coalescing, subtraction, and division expressions.	Weak warning
Loop can be replaced with 'implode()'	Reports the `foreach` loops that can be safely replaced with `implode()` calls. See implode (php.net) for details.	Weak warning
Loop can be replaced with 'str_repeat'	Reports the `for` loops that can be safely replaced with `str_repeat()` calls.	Weak warning
Method visibility should not be overridden	Checks that the methods don't override visibility. Overriding a `protected` method with a `public` method in a child class makes this method accessible from everywhere. This violates the encapsulation principle and is considered bad practice. See Method Visibility (php.net) for details.	Disabled
Method's return value is never used	Reports the private methods returning the values that are not used.	Weak warning
Modulo operation with '1' as operand	Reports the modulo expressions `%` that always evaluate to `0` or `1`.	Weak warning
Nested 'dirname()' call can be replaced with 'levels' parameter usage	Reports the nested `dirname()` calls that can be omitted by using the `levels` parameter instead.	Weak warning
Nested 'min/max' call	Reports nested `min`/`max` calls. Since the `min`/`max` functions accept any number of arguments, such nested calls are redundant.	Weak warning
Parameter's value is always the same	Reports the parameters in private methods that have the same value across all method calls.	Weak warning
Parameters number mismatch declaration	Reports the function/method calls that take more parameters than specified in their declaration.	Weak warning
Private property can be local	Reports the private properties that are used only in a single method. Such properties can be replaced with local variables.	Weak warning
Property usages have same access	Reports the private properties that are: written but never read read but never written	Warning
Redundant 'array_values' call on a value iterated in 'foreach'	Reports the `array_values()` calls inside `foreach` loops in which the iterated value is used without a key. Such calls are redundant and can be safely removed.	Weak warning
Redundant 'continue/break' argument	Reports the redundant `1` argument of `continue` and `break` statements. Since this argument is optional and its default value is `1`, such usages can be omitted. See continue (php.net) and break (php.net) for details.	Weak warning
Redundant 'static' in final class	Reports `static` usages inside final class	Weak warning
Redundant assignment to promoted property	Reports redundant assignments to class properties that duplicate automatic assignments performed through promoted constructor parameters. See Constructor Property Promotion (php.net) for details.	Weak warning
Redundant cast to boolean	Reports the `(bool)`/`(boolean)` casts and `boolval()` calls that are redundant since casting to `bool` is performed implicitly.	Weak warning
Redundant cast to string	Reports the `(string)` casts and `strval()` calls that are redundant since casting to string is performed implicitly.	Weak warning
Redundant method override	Reports the overriding methods that only consist of a single call to the parent method.	Weak warning
Redundant optional argument	Reports redundant arguments that match the corresponding default values for optional parameters.	Weak warning
Ternary expression can be replaced with condition	Reports the ternary expressions specified as `condition ? true : false` that can be safely replaced with just `condition`.	Weak warning
Ternary expression can be replaced with short version	Reports the `?:` ternary expressions in which the condition and the `true` statement are matching.	Weak warning
Too many parameters in function declaration	Reports the function/method declarations with the number of parameters exceeding the specified limit.	Disabled
Unnecessary 'return/continue' statement	Reports unnecessary `return` and `continue` statements that can be safely removed.	Weak warning
Unnecessary local variable	Reports the local variables that are used in exit statements, such as `throw`, `return`, or `yield`, immediately after assignment.	Weak warning
Unnecessary pass-by-ref	Reports the variables that are passed by reference to a function/method but are not modified in the function/method body. In such cases, the `&` in parameter's declaration can be safely removed. See Passing by Reference (php.net) for details.	Weak warning
Unnecessary semicolon	Reports unnecessary semicolons.	Weak warning
Unnecessary spread operator for function call argument	Reports the usages of the spread operator (`...`) on array literals in function call arguments that may be safely unwrapped.	Weak warning
Usage of a silence operator	Reports the usages of the silence operator (`@`), which is highly discouraged. See Error Control Operators (php.net) for details.	Disabled
Useless trailing comma	Reports the trailing commas in parameters lists and closures' `use` lists that do not bring any benefit. In a single-line list, a trailing comma is redundant and can be removed. In a multiline list, if no line break is provided after a trailing comma, it becomes impossible to easily add, remove, or move lines.	Weak warning

PHP strict standards

Inspection	Description	Default Severity
Declaration of overridden method should be compatible with parent class	Reports the overridden methods declarations that are not compatible with the parent class. The inspection is enabled only for the PHP language level lower than 8.0.	Warning
Static function should not be abstract	Reports the static methods that are declared as abstract.	Warning

Code style

Inspection	Description	Default Severity
'Closure::fromCallable()' can be converted to the first-class callable syntax	Reports the `callable` creation expressions that use `Closure::fromCallable` but can be replaced with first-class callable syntax `f(...)` available since PHP 8.1. See First-class callable syntax (php.net) for details.	Weak warning
'array_fill' can be converted to loop	Reports the `array_fill()` calls that can be replaced with `foreach` loops.	No highlighting, only fix
'array_filter()' call can be converted to loop	Reports the `array_filter()` calls that can be replaced with `foreach` loops.	No highlighting, only fix
'array_map()' call can be converted to loop	Reports the `array_map()` calls that can be replaced with `foreach` loops.	No highlighting, only fix
'get_class()' call can be replaced with '::class'	Reports the `get_class()` calls and suggests replacing them with `::class` when PHP Language level is set to 8.0 or later. See Allow ::class on objects (php.net) for details.	No highlighting, only fix
'isset' can be replaced with coalesce	Reports the conditions using `isset` that can be safely replaced with expressions using the `??` null coalesce operator. See Null coalesce operator (php.net) for details.	Weak warning
'match' can be replaced with 'switch' statement	Reports the `match` expressions that can be replaced with `switch` statements. Note that `match` expressions use strict type comparison, while `switch` statements rely on loose comparison. As a result, the expression semantics may change after replacement. See match (php.net) and switch (php.net) for details.	No highlighting, only fix
'match' expression can be replace with ternary expression	Reports the `match` expressions containing a default arm and a single non-default arm. Such `match` expressions can be replaced with ternary expressions. See Match expression (php.net) for details.	No highlighting, only fix
'mixed' return type can be narrowed	Reports 'mixed' return types that can be narrowed down to more concrete types.	Weak warning
'mixed' type can be replaced with 'array'	Reports the `mixed[]` usages in PHPDoc blocks that can be safely replaced with `array`.	Weak warning
'str()' calls can be replaced with PHP 8 'str_()' calls	Reports the `strpos` and `substr` functions calls that can be replaced with the `str_*` functions calls (introduced in PHP 8.0). See str_contains (php.net) and str_starts_with and str_ends_with functions (php.net) for details.	Weak warning
'switch' can be replaced with 'match' expression	Reports 'switch' statements that could be replaced with 'match' expression	Weak warning
Automatic conversion of 'false' to array is deprecated	Reports automatic conversions of `false` values to arrays. Such expressions are deprecated starting from PHP 8.1. See Deprecate autovivification on false for details.	Weak warning
Case mismatch in method call or class usage	Reports the usages of functions, methods, classes, and namespaces that do not match the case used in their declarations.	Disabled
Class path doesn't match project structure	Reports the classes with the filepath not following the PSR-0/PSR-4 project structure. You can configure the project vendor roots under Settings/Preferences \| Directories. See PSR-0/PSR-4 standards (php-fig.org) for details.	Warning
Closure can be converted to arrow function	Reports the anonymous functions that can be transformed to short arrow functions. Support for short arrow functions is available since PHP 7.4. See PHP RFC: Arrow Functions 2.0 (php.net) for details.	No highlighting, only fix
Comment can be replaced with named argument	Reports the inline comments before arguments in function calls that only contain the name of the parameter and thus serve as hints. In PHP 8.0 and later, named arguments can be used instead. See Named arguments (php.net) for details.	Weak warning
Control statement body without braces	Reports the control structures (such as loops or conditionals) whose bodies are not enclosed in braces. See Control structures (php.net) for details.	No highlighting, only fix
Dangerous array initialization	Reports dangerous array initializations (such as `$arr[] = value`). This practice is discouraged because if `$arr` already contains some value (for example, a string from a request variable), then this value will stay in place and `[]` may actually stand for string access operator. It is always preferable to initialize a variable by direct assignment. See Creating/modifying with square bracket syntax (php.net) for details.	No highlighting, only fix
Define constant name can be replaced with 'const' syntax	Reports the `define()` calls that can be replaced with `const` syntax.	Weak warning
Enforce PHPDoc comment	Reports the elements without a PHPDoc comment or with a PHPDoc comment only containing the `@noinspection` tag. You can use Missing PHPDoc Comment inspection to report only non-fully typed elements.	Disabled
Expression without clarifying parentheses	Reports potentially ambiguous expressions and proposes enclosing them in clarifying parentheses.	No highlighting, only fix
Fully qualified name usage	Reports the fully qualified class names that can be shortened by adding the `use` statement.	Weak warning
Implicit octal literal can be replaced with explicit one	Reports the implicit octal literals such as `071` that could be replaced with explicit ones such as 0o71. Explicit octal literals using the `0o/0O` prefix are supported in PHP 8.1 and later. See Explicit octal integer literal notation (php.net) for details.	No highlighting, only fix
Loop can be converted to 'array_fill()' call	Reports the `for` loops that can be replaced with `array_fill()` calls.	No highlighting, only fix
Loop can be converted to 'array_filter()' call	Reports the `foreach` loops that can be replaced with `array_filter()` calls.	No highlighting, only fix
Loop can be converted to 'array_map()' call	Reports the `foreach` loops that can be replaced with `array_map()` calls.	No highlighting, only fix
Method can be made 'static'	Reports the methods that don't use any instance references and thus may be converted to static methods.	No highlighting, only fix
Missing @throws tag(s)	Checks that the PHPDoc block contains the `@throws` tag for each exception thrown by a function/method. The exception classes added to the Unchecked Exceptions list under Settings/Preferences \| PHP \| Analysis are excluded from the inspection scope.	Weak warning
Missing PHPDoc comment	Reports non-fully typed elements without a PHPDoc comment or with a PHPDoc comment only containing the `@noinspection` tag. You can use the Enforce PHPDoc Comment inspection to report fully typed elements.	Disabled
Multiple classes declarations in one file	Reports multiple class declarations in a single file, which violates the PSR-0/PSR-4 standards. See PSR-0/PSR-4 standards (php-fig.org) for details.	Weak warning
Named arguments order does not match parameters order	Reports named argument with order that does not match parameter order	Weak warning
Non-canonical order of elements	Reports the PHPDoc tags that have elements listed in non-canonical order. For example, for such tags as `@property`, `@param`, or `@var`, the inspection will report the usages of `[name] ["Type"]` instead of `["Type"] [name]`.	Disabled
Nullsafe operator '?->' can be used	Reports the null-checking conditional expressions that can be safely replaced with the `?->` nullsafe operator.	Weak warning
Old style constructor	Reports old-style constructor declarations (`ClassName()`) and suggests replacing them with new-style constructors (`__construct()`). Prior to PHP 8.0, old-style constructor syntax used in the classes in the global namespace is treated as deprecated and will result in an `E_DEPRECATED` error. If both a `__construct()` and a `ClassName()` method are defined, `__construct()` will be called. In namespaced classes, or any classes as of PHP 8.0, a `ClassName()` method never has any special meaning and will never be called as a constructor. As a result, the inspection does not report such cases if the PHP language level is set to 8.0 or later. See Constructors and destructors (php.net) for details.	Warning
PHPDoc comment signature is not complete	Reports the PHPDoc comments that contain at least one `@param` or `@return` tag but are missing some of the `@param` or `@return` tags for parameters or return types specified in the function/method declaration.	Weak warning
Redundant closing tag	Reports PHP closing tag `?>` usages, which are redundant in files containing only PHP code.	Weak warning
Short open tag usage	Reports short PHP opening tag `<?` usages. Since short tags can be disabled in the PHP interpreter configuration, using them may lead to code compatibility issues. See PHP tags (php.net) for details.	Warning
Single-statement body with braces	Reports the control structures (such as loops or conditionals) whose bodies are enclosed in braces but only contain a single child statement. Using braces in such cases is not necessary. See Control structures (php.net) for details.	No highlighting, only fix
Traditional syntax array literal detected	Reports traditional array syntax (`array()`) usages in array literals and suggests replacing them with short array syntax (`[]`).	Disabled
Trait usage is not allowed	Reports the class references that are resolved to traits but are specified outside `use` statements. Such usages are most probably the result of a programming mistake, since traits cannot be instantiated and any `instanceof`-like behaviour is not supported for traits by design. See Traits (php.net) for details.	Weak warning
Trait use rule resolved to method with different containing class	Reports the trait method `use` rules that are resolved to methods from a different containing class rather than the one specified in the `use` declaration.	Weak warning
Type cast is unnecessary	Reports the type cast operators used on the values that are already of the corresponding type. Such operators are redundant and can be safely removed. See Type juggling (php.net) for details.	Weak warning
Type cast on a scalar value	Reports the type casts that can be evaluated in place and suggests replacing them with actual computed values. See Type juggling (php.net) for details.	Weak warning
Unnecessary curly braces syntax for variable	Reports unnecessary `{` and `}` used for interpolating variables in string literals. See Variable parsing (php.net) for details.	Weak warning
Unnecessary double quotes	Reports double-quoted string literals that do not contain string interpolation, escape sequences, or single quotes.	Disabled
Unnecessary fully qualified name	Reports the usages of fully qualified class names, which can be shortened without adding the `use` statement.	Weak warning
Unnecessary leading '\' in 'use' statement	Reports the `use` statements with an unnecessary leading `\`. For namespaced names (fully qualified namespace names containing a namespace separator, such as `Foo\Bar` as opposed to global names that do not, such as `FooBar`), the leading backslash is unnecessary and not recommended, as import names must be fully qualified and are not processed relative to the current namespace. See Using namespaces: Aliasing/Importing (php.net) for details.	Weak warning
Unnecessary parentheses	Reports the expressions containing redundant parenthesis, which can be safely removed.	No highlighting, only fix
Usage of a variable variable	Reports the usages of variable variables (dynamic variable names such as `$$a`).	Disabled

Probable bugs

Inspection	Description	Default Severity
Assignment in condition	Reports the assignments that are used in conditional expressions.	No highlighting, only fix
Case with specified value not found in enum	Reports the arguments of enum's `from` method calls that are not found in target enum classes. See Enumerations (php.net) for details.	Error
Concatenation with arithmetic usage	Reports the string concatenation expressions that are used together with `+`, `-`, `<<`, and `>>` operators. Starting with PHP 8, the concatenation operation has lower precedence and such expressions can thus produce unexpected results. See Concatenation precedence (php.net) for details.	Warning
Constant reassignment	Reports reassignments of constants. Since constants cannot be changed, such assignments will have no effect and will emit an `E_NOTICE` (in PHP 7.4 and earlier) or `E_WARNING` (in PHP 8.0 and later).	Warning
Division by zero	Reports division by zero or modulo by zero.	Error
Duplicate arm in 'match' expression	Reports duplicate bodies in `match` arms. See Match expression (php.net) for details.	Weak warning
Duplicate array keys	Reports duplicate keys in array declarations. If multiple elements in the array declaration use the same key, only the last one will be used, and all others will be overwritten.	Warning
Duplicate branch in switch statement	Reports the `switch` statements containing the same code in different branches.	Weak warning
Duplicate case in switch statement	Reports duplicate `case` expressions in `switch` statements. If a `switch` statement contains multiple duplicate `case` expressions, only the first one is executed.	Warning
Duplicate character in function call	Reports duplicate characters provided in the `characters` argument of functions like `ltrim` or `str_words_counts`. Such duplicates are most probably a mistake and can be safely removed.	Warning
Duplicate condition	Reports duplicate conditions in `match` expressions. See Match expression (php.net) for details.	Warning
Empty index operator not supported for strings	Reports the usages of empty index operator (`[]`) on strings. Starting from PHP 7.1, applying the empty index operator on a string throws a fatal error. See Creating/modifying with square bracket syntax (php.net) for details.	Error
Expression result unused	Reports the expressions that are calculated, but the calculation result is not used anywhere. Such errors can be caused, for example, by misspelling the `=` operator as `==`.	Warning
Foreach array is used as value	Reports the variables that are used in a `foreach` loop as both an array expression and an array's key or value (for example, `foreach ($items as $items) {}`). Commonly, this is the result of a typing error.	Warning
Format function parameters mismatch	Reports the arguments of a format function (such as `printf` or `sprintf`) that are not mapped to any parameters or specification conversions. See printf (php.net) and sprintf (php.net) for details.	Warning
Goto into loop statement	Reports the `goto` labels that are located inside loops or `switch` statements. See goto (php.net) for details.	Error
Invalid string offset usage	Reports invalid string offset usages that will result in a runtime error. The following usages are reported: Using string offsets as objects or arrays Unsetting string offsets via `unset` Passing string offsets by reference Creating references to or from string offsets Incrementing or decrementing string offsets Using combined operator assignments such as `+=` or `.=` on string offsets Assigning string offsets with empty strings or strings with length >1	Error
Invalid type of unpacked argument	Reports unpacked function arguments and array elements whose type is neither `array` nor `Traversable`. Starting with PHP 8.0, such usages will result in `Fatal error`.	Warning
Local object is used only for writing properties	Reports the variable assignments to new objects that are used only for writing the object's properties without observable side effects.	Warning
Method '__toString' implementation	Reports the attempts to convert the objects having no `__toString` method implementation to `string`. Prior to PHP 7.4, this would lead to a fatal `E_RECOVERABLE_ERROR` level error. In PHP 7.4, a fatal non-recoverable `ERROR` is thrown. In PHP 8.0, the return value follows the standard PHP type semantics and will be coerced into a string if possible and if strict typing is disabled. If the Check __toString exists for each expression type option is enabled, the inspection will check all possible types of the expression and report if at least one of them doesn't contain the `__toString` method implementation. See __toString (php.net) for details.	Warning
Method '__toString' return type	Reports the `__toString` methods that do not return `string`. Prior to PHP 7.4, this would lead to a fatal `E_RECOVERABLE_ERROR` level error. In PHP 7.4, a fatal non-recoverable `ERROR` is thrown. In PHP 8.0, the return value follows the standard PHP type semantics and will be coerced into a string if possible and if strict typing is disabled. See __toString (php.net) for details.	Error
Missing 'break' statement	Reports the `case` clauses in `switch` statements that do not end with a `break` or a `return` statement. If a `case` clause does not end with `break` or `return`, its execution can unintentionally fall through the next case.	Weak warning
Missing parent call for constructor	Reports the constructors that do not call their parent constructor.	Warning
Missing parent call for magic methods	Reports the magic methods that do not call their parent magic method.	Disabled
Missing parent call for method	Reports the methods that do not call their parent method.	Disabled
Nested vs outer 'foreach' variables conflict	Reports the variables that are used as a key or value both by the inner and outer `foreach` loops. In most cases, this is an error or may result in an error in the future.	Warning
Non-strict object equality	Reports the usages of the comparison operator (`==`) for comparing object variables. Object variables are compared as follows: When using the comparison operator (`==`), two object instances are considered equal if they have the same attributes and values (values are compared with `==`), and are instances of the same class. When using the identity operator (`===`), object variables are considered identical if and only if they refer to the same instance of the same class. See Comparing Objects (php.net) for details.	Weak warning
Optional before required parameter	Reports the optional parameters that appear before the required parameters in a function/method declaration. See Default argument values (php.net) for details.	Warning
Pass parameter by reference	Reports the arguments in a function/method call that cannot be passed by reference. Only variables and references returned from functions can be passed by reference. See Passing by Reference (php.net) for details.	Error
Redundant assignment	Reports the assignment statements, in which both sides are equal. Such assignments have no effect and can be removed.	Warning
Some enum cases are uncovered	Reports the `match` expressions that don't cover all `enum` cases in `match` arm conditions.	Weak warning
Statement has empty body	Reports the statements that have empty bodies. While occasionally useful, such statements are often the result of typos and may cause confusion.	Warning
Strict comparison of operands with incompatible types	Reports the `===` or `!==` strict comparisons used on operands with incompatible types. See PHP type comparison tables (php.net) for details.	Weak warning
Suspicious names combination	Reports the assignments and function calls where the name of the variable or parameter probably doesn't match the name of the assigned or passed value. The following sets of names are supported: `needle`, `haystack` `x`, `y` `top`, `bottom`, `left`, `right` `year`, `month`, `week`, `day`, `hour`, `minute`, `second`	Warning
Switch statement without default branch	Reports the `switch` statements without a default branch.	No highlighting, only fix
Unnecessary statement use	Reports the `use` statements that contain non-fully qualified class names and thus have no effect. The inspection only reports classes imports; functions and constants imports are not considered. See Using namespaces: Aliasing/Importing (php.net) for details.	Warning
Unused 'match' condition	Reports the conditions in `match` expressions that will never be matched. Similarly to PHP Engine behavior, the inspection uses strict comparison (`===`) to check the types in `match` conditions against the `match` argument type, regardless of the `strict_types` directive. Since no type coercion occurs, some conditions may be non-matched due to non-matching types. See Match expression (php.net) for details.	Weak warning
Unused 'switch' branch	Reports the branches in `switch` statements that do not belong to the set of enum cases and as a result are never executed. See Enumerations (php.net) for details.	Weak warning
Void function result used	Reports the usages of a `void` function's return value. Since `void` functions do not have a return value, such usages are most likely a programming mistake.	Warning
Wrong string concatenation	Reports the attempts to concatenate strings by using the `+` operator instead of the dot (`.`) concatenation operator. Such attempts are most likely a programming mistake.	Warning

Regular expressions

Inspection	Description	Default Severity
Asterisk closure can be collapsed to plus closure	Reports the regular expression patterns that comprise repeating characters ending with an asterisk `` (for example, `aa`). Such patterns can be replaced with `a+`.	Weak warning
Element in class is already covered	Reports the elements in regular expression character classes that are already covered by another element in the same class. Such elements are redundant and can be safely removed.	Weak warning
Ranges in class can be merged	Reports the alphabetic ranges or characters in regular expression character classes that only adjust the already existing ranges. Such elements can be merged with the adjusted ranges.	Weak warning

Naming conventions

Inspection	Description	Default Severity
Class name is not following coding convention	Reports the classes' names that are either too short, too long, or do not follow the specified regular expression pattern. Some coding styles have a special naming convention for classes. Use the inspection options to specify minimum/maximum length and the regular expression expected for classes' names. To ignore the names' length, specify 0. To learn more about regular expressions, refer to the Quick Start guide (regular-expressions.info).	Disabled
Constant name is not following coding convention	Reports the constants' names that are either too short, too long, or do not follow the specified regular expression pattern. Some coding styles have a special naming convention for constants. Use the inspection options to specify minimum/maximum length and the regular expression expected for constants' names. To ignore the names' length, specify 0. To learn more about regular expressions, refer to the Quick Start guide (regular-expressions.info).	Disabled
Function name is not following coding convention	Reports the functions' names that are either too short, too long, or do not follow the specified regular expression pattern. Some coding styles have a special naming convention for functions. Use the inspection options to specify minimum/maximum length and the regular expression expected for functions' names. To ignore the names' length, specify 0. To learn more about regular expressions, refer to the Quick Start guide (regular-expressions.info).	Disabled
Method name is not following coding convention	Reports the methods' names that are either too short, too long, or do not follow the specified regular expression pattern. Some coding styles have a special naming convention for methods. Use the inspection options to specify minimum/maximum length and the regular expression expected for methods' names. To ignore the names' length, specify 0. To learn more about regular expressions, refer to the Quick Start guide (regular-expressions.info).	Disabled
Property name is not following coding convention	Reports the properties' names that are either too short, too long, or do not follow the specified regular expression pattern. Some coding styles have a special naming convention for properties. Use the inspection options to specify minimum/maximum length and the regular expression expected for properties' names. To ignore the names' length, specify 0. To learn more about regular expressions, refer to the Quick Start guide (regular-expressions.info).	Disabled
Variable name is not following coding convention	Reports the variables' names that are either too short, too long, or do not follow the specified regular expression pattern. Some coding styles have a special naming convention for variables. Use the inspection options to specify minimum/maximum length and the regular expression expected for variables' names. To ignore the names' length, specify 0. To learn more about regular expressions, refer to the Quick Start guide (regular-expressions.info).	Disabled

General

Inspection	Description	Default Severity
Argument with name identifier	Reports arguments with name identifiers.	No highlighting, only fix
Argument without name identifier	Reports arguments without name identifiers.	No highlighting, only fix
Array index is immediately rewritten	Reports the write expressions on array indexes which are immediately overwritten before being accessed.	Warning
Class can't implement Traversable directly	Reports the classes that are implementing the `Traversable` interface alone, not as part of `Iterator` or `IteratorAggregate` interfaces. The `Traversable` interface is an internal engine interface; it cannot be implemented in PHP scripts. See The Traversable interface (php.net) for details.	Error
Class hierarchy checks	Checks the classes' hierarchy: abstract methods implementation, the compatibility of implementing/overriding methods with their declarations in parent classes, and properties' types redeclarations. All reported violations result in PHP fatal errors. It is not recommended disabling or suppressing this inspection.	Error
Curly brace access syntax usage	Reports the usages of curly brace syntax for accessing array elements and string offsets.	Error
Deprecated	Reports the usages of deprecated entities. In most cases, such usages should be removed or replaced with other constructs.	Weak warning
Deprecated 'Serializable' interface usage	Reports the usages of deprecated `Serializable` interface. Starting from PHP 8.1, classes that are non-abstract, implement `Serializable`, and do not implement `__serialize()` and `__unserialize()` will throw a deprecation warning. See Phasing out Serializable (php.net) for details.	Warning
Deprecated 'implode/join' usage	Reports deprecated usage of the `implode` and `join` functions. Starting from PHP 7.4, using `implode` and `join` with an array as the first argument and a string as the second argument is deprecated. See Deprecations for PHP 7.4 (php.net) for details.	Warning
Deprecated Standard Library call	Reports the calls to Standard PHP Library functions that are deprecated starting from PHP 8.1. The following calls are reported: `key()`, `current()`, `next()`, `prev()`, and `reset()` calls with objects as arguments. `mb_check_encoding()` calls without arguments. `get_class()`, `get_parent_class()` and `get_called_class()` calls without arguments. `IntlCalendar::roll()` calls with a Boolean passed as the `$value` argument. `ctype_*()` calls with non-string arguments. See PHP RFC: Deprecations for PHP 8.1 for details.	Warning
Deprecated cast	Reports deprecated cast expressions: `(unset)` cast expressions, which are deprecated in PHP 7.2 and later. `(real)` cast expressions, which are deprecated in PHP 7.4 and later. See Deprecated features in PHP 7.2.x (php.net) and Deprecations for PHP 7.4 (php.net) for details.	Weak warning
Disabled extension stubs	Reports the usages of classes, functions, and constants, for which the stubs for the corresponding PHP interpreter extensions are disabled. You can configure the set of stubs under Settings/Preferences \| PHP \| PHP Runtime. See PhpStorm stubs (blog.jetbrains.com/phpstorm) for details.	No highlighting, only fix
Dynamic method called as static	Reports static calls to dynamic class methods. For classes having the magic method `__callStatic`, a separate inspection severity and highlighting level can be set.	Warning
Element is not available in configured PHP version	Reports the usages of entities which were introduced in PHP version later than configured one.	Error
Ignored class alias declaration	Reports the class alias declarations that are ignored by the IDE because the actual class declaration with the same FQN exists. The inspection is intended to clarify the IDE’s behavior in the cases when both the class and the class alias declarations are present. When several declarations with the same FQN exist, the IDE usually fails to choose a single one between them. This leads to incorrect code completion, erroneous type inference, and so on. Since the class declaration prevails over the class alias declaration, the latter becomes redundant and therefore ignored by the IDE. Note that ignoring class alias declarations does not affect the behavior of the PHP interpreter.	Weak warning
Incorrect magic method signature	Reports incompatible magic methods signatures. See RFC: Ensure correct signatures of magic methods (php.net) for details.	Error
Invalid magic method modifiers	Reports the magic methods that are not declared as public or are declared as static.	Warning
Language level	Reports the language features used in source code that are not supported for the selected language level. For example, union types can be used only in PHP 8.0 and later.	Error
Method declaration in parent class is incompatible with implemented interface	Reports the methods declarations in parent classes that are incompatible with implemented interfaces.	Error
Named argument may be unresolved	Reports the named arguments in method calls that might be unresolved depending on a specific class instance within the hierarchy.	Weak warning
Nested ternary operator usage	Reports nested ternary expressions, which are deprecated starting from PHP 7.4.	Error
Parameter's name changed during inheritance	Reports the methods' parameters whose names differ from the same parameters defined in parent methods. Starting with PHP 8.0, such code can cause runtime errors.	Weak warning
Promoted property usage	Reports properties declared through promoted constructor parameters. Using promoted properties is only possible since PHP 8.0. In earlier PHP versions, it leads to a parse error. See Constructor Property Promotion (php.net) for details.	No highlighting, only fix
Property can be promoted	Reports the properties that can be replaced with promoted versions. See Constructor Property Promotion (php.net) for details.	No highlighting, only fix
Property is immediately rewritten	Reports the write expressions on properties which are immediately overwritten before being accessed.	Warning
Second write to 'readonly' property	Reports reassignments of `readonly` properties. Such properties cannot be modified after initialization. See Readonly properties (php.net) for details.	Error
Static method called as dynamic	Reports dynamic calls to static class methods. If the target has the magic method `__call`, a separate inspection severity and highlighting level can be set.	Disabled
Unresolved include	Reports non-resolved `include`, `include_once`, `require`, and `require_once` expressions.	Weak warning
Usage of internal entity	Reports the usages of the entities that are marked as `@internal` and are located in different source roots. The usages located in the same source root are not reported. In most cases, the reported usages should be removed or replaced with other constructs.	Weak warning
Write access to 'readonly' property outside of declaration scope	Reports the write accesses to `readonly` properties that are made outside the declaration scope. A declaration scope effectively means non-static methods of the class in which a property is declared. See Readonly properties (php.net) for details.	Error

Error handling

Inspection	Description	Default Severity
Redundant catch clause	Reports the `catch` clauses with exceptions that are never thrown from the corresponding `try` block.	Weak warning
Unhandled exception	Reports the exceptions that are neither enclosed in a `try-catch` block nor documented via the `@throws` tag.	Weak warning
Wrong catch clauses order	Reports the exceptions that are already caught by a preceding exception and the exceptions that are caught twice. The `catch` clauses must be ordered from more specific to more generic ones. Otherwise, some exceptions may not be caught by the most specific handler. See Exceptions (php.net) for details.	Warning

Inspection

Description

Default Severity

Redundant catch clause

Reports the catch clauses with exceptions that are never thrown from the corresponding try block.

Weak warning

Unhandled exception

Reports the exceptions that are neither enclosed in a try-catch block nor documented via the @throws tag.

Weak warning

Wrong catch clauses order

Reports the exceptions that are already caught by a preceding exception and the exceptions that are caught twice.

The catch clauses must be ordered from more specific to more generic ones. Otherwise, some exceptions may not be caught by the most specific handler.

See Exceptions (php.net) for details.

Warning

Type compatibility

Inspection	Description	Default Severity
'null' is not compatible with parameter's declared type	Reports the variables that are initialised via passing them by reference to a parameter incompatible with `null`.	Error
Arithmetic operation with unsupported operands	Reports arithmetic and bitwise expressions with unsupported operands. Starting with PHP 8.0, using the arithmetic and bitwise operators `+`, `-`, ``, `/`, `*`, `%`, `<<`, `>>`, `&`, `\|`, `^`, `~`, `++`, `--` when one of the operands is an array, resource, or non-overloaded object will result in a `TypeError`. The only exception is the `array + array` merge operation, which remains supported. See PHP's internal test source for the complete list of operations.	Error
Array offset access on illegal type	Reports the array offset access expressions that are used on illegal types.	Weak warning
Illegal array key type	Reports the array keys that are of illegal type, such as objects or arrays. See Arrays (php.net) for details.	Warning
Illegal string offset	Reports the usages of non-`integer` offsets in string access expressions such as `$str[42]`. Starting from PHP 5.4, string offsets have to be either integers or integer-like strings. Since it's considered bad practice to use strings as a string offset, the inspection reports them, as well. See String access and modification by character (php.net) for details.	Warning
Incompatible return type	Reports the `return` statements whose return value type is not compatible with the one declared for a function/method.	Warning
Invalid argument supplied for 'foreach()'	Reports the `foreach` constructs used on variables of the `string`, `float`, `int`, or `boolean` type. See foreach (php.net) for details.	Warning
Missing parameter's type declaration	Reports the parameters that have no type declaration specified.	Weak warning
Missing property's type declaration	Reports the properties that have no type declaration.	Weak warning
Missing return type declaration	Reports the functions that have no return type declaration specified.	Weak warning
Missing strict types declaration	Detects the missing `declare(strict_types=1)` directive in the file. See Strict typing (php.net) to learn more about why you may need use this directive.	Disabled
Parameter type	Reports the parameters passed to a function call, whose types do not match the ones specified in the function definition via type declaration or the PHPDoc `@param` tag. See Type declarations (php.net) and @param (phpdoc.org) for details.	Warning
Redundant intersection type	Reports the intersection type declarations that contain redundant types, for example, an intersection type that contains both the parent class and its subclass. See PHP RFC: Pure intersection types (php.net) for details.	Weak warning
Strict type checking rules violation	Reports violations of the strict type checking rules. In strict mode, only the variables exactly matching the declaration types are accepted. Strict type-checking mode can be enabled: Per file, if the `declare(strict_types=1)` directive is specified. The directive must be the first statement in a file, block mode is explicitly disallowed. For all files, if the Enable for all files inspection option is enabled. See Strict typing (php.net) for details.	Error
Type declaration is redundant and could be simplified	Reports union type declarations that contain redundant types, for example, a union type that contains both the class alias and the original class. See Union Types RFC: Duplicate and redundant types (php.net) for details.	Weak warning
Type mismatch in property assignment	Reports type violations in properties assignments.	Warning

Undefined symbols

Inspection	Description	Default Severity
Multiple class declarations	Reports the references to classes that have multiple declarations in project files. Use the options below to customize the inspection: Ignore PHPDoc: if selected, the inspection will not report multiple declarations of classes referenced in PHPDoc blocks.	Weak warning
Possible polymorphic call	Reports polymorphic code usages. Such usages are ambiguous and can be potentially inoperable depending on the class instance passed as the argument.	Weak warning
Undefined callback	Reports the functions, methods, properties, or classes that are referenced from a callback but are not found. Use the options below to customize the inspection: Ignore callback from *_exists and is_callable functions: if selected, the inspection will skip callback references from the `method_exists`, `function_exists`, `property_exists`, `class_exists` and `is_callable` functions. Don't report in case of ambiguity: if selected, the inspection will skip the parameters with multiple possible types, for example marked as `callable\|string`.	Disabled
Undefined class	Reports the references to classes whose declarations are not found in the project files, configured include paths, or among the PHP predefined classes. Use the options below to customize the inspection: Ignore PHPDoc: if selected, the inspection will not report the undefined classes referenced in PHPDoc blocks.	Warning
Undefined class constant	Reports the references to class constants that are not declared.	Error
Undefined constant	Reports the references to constants that are not found in the project files, configured include paths, or among the PHP predefined constants.	Warning
Undefined function	Reports the references to functions that are not defined in the project files, configured include paths, or among the PHP predefined functions.	Warning
Undefined goto label	Reports the `goto` labels that are not found in the current scope. The target `goto` label must reside in the same file and context: you cannot jump into or out of a function or method, and cannot jump into a loop or switch structure. See goto (php.net) for details.	Warning
Undefined method	Reports the references to class methods that are not defined.	Warning
Undefined namespace	Reports the references to a namespace that is not found.	Warning
Undefined property	Reports the references to class properties that are not declared. The inspection skips the objects of the `stdClass` or derived types.	Warning
Undefined variable	Produces two types of warnings: Undefined variable: the variable's definition is not found in the project files, configured include paths, or among the PHP predefined variables. Variable might have not been defined: there are one or more paths to reach the line with the variable usage without defining it. Use the options below to customize the inspection: Report that variable is probably undefined: clear the checkbox to disable the Variable might have not been defined warnings. Enable inspection in global space: by default, the inspection is enabled for global space. Clear the checkbox to only report undefined variables from functions' local scope. Search for variable's definition outside the current file: if selected, the IDE reports a global variable as undefined only in case there are no `include` or `require` statements in the current file and the variable's definition cannot be found in the project. Otherwise, if not selected, the IDE searches for the variable's definition only in the current file and ignores the `include` or `require` statements if any.	Error

Quality tools

Inspection	Description	Default Severity
PHP CS Fixer validation	Reports coding style problems detected by PHP CS Fixer. The inspection requires PHP CS Fixer to be properly installed and set up in the IDE under Settings/Preferences \| PHP \| Quality Tools \| PHP CS Fixer. To learn more about installing PHP CS Fixer, see PHP-CS-Fixer installation (GitHub).	Disabled
PHP Mess Detector validation	Reports coding style problems detected by PHP Mess Detector. The inspection requires PHP Mess Detector to be properly installed and set up in the IDE under Settings/Preferences \| PHP \| Quality Tools \| Mess Detector. To learn more about installing PHP Mess Detector, see PHP Mess Detector installation (phpmd.org) for details. You can use a predefined set of rules or add your own by specifying valid ruleset.xml files. See the rules index (phpmd.org) and How to create a custom rule set (phpmd.org) for details.	Disabled
PHPStan validation	Runs PHPStan to find code problems. The inspection requires PHPStan to be properly installed and set up in the IDE under Settings/Preferences \| PHP \| Quality Tools \| PHPStan. To learn more about installing PHPStan, see: https://phpstan.org/user-guide/getting-started	Disabled
PHP_CodeSniffer validation	Reports coding style problems detected by PHP_CodeSniffer. The inspection requires PHP_CodeSniffer to be properly installed and set up in the IDE under Settings/Preferences \| PHP \| Quality Tools \| PHP_CodeSniffer. To learn more about installing PHP_CodeSniffer, see PHP_CodeSniffer installation (GitHub).	Disabled
Psalm validation	Runs Psalm to find code problems. The inspection requires Psalm to be properly installed and set up in the IDE under Settings/Preferences \| PHP \| Quality Tools \| Psalm. To learn more about installing Psalm, see: https://psalm.dev/docs/running_psalm/installation/	Disabled

Unused symbols

Inspection	Description	Default Severity
Redundant property initializer	Reports the fields with default initializers that are always overwritten in the class constructor.	Weak warning
Unused declaration	Reports the classes, methods, functions, constants, or properties that are not used or not reachable from entry points. It also reports all method implementations/overriders. Some unused members might not be reported in the code editor on the fly. Due to performance reasons, a non-private member is checked only when its name rarely occurs in the project. To see all results, run the inspection in batch mode by using Code \| Inspect Code... or Code \| Run Inspection by Name....	Weak warning
Unused import	Reports the imports that are never used.	Weak warning
Unused local variable	Reports the variables that are considered unused in the following cases: The value of the variable is not used anywhere or is overwritten immediately. The reference stored in the variable is not used anywhere or is overwritten immediately.	Weak warning
Unused parameter	Reports the parameters that are considered unused in the following cases: The parameter is passed by value, and the value is not used anywhere or is overwritten immediately. The parameter is passed by reference, and the reference is not used anywhere or is overwritten immediately.	Weak warning
Unused private method	Reports the private methods that are never used.	Weak warning
Unused private property	Reports the private properties that are never used.	Weak warning

Refactoring opportunities

Inspection	Description	Default Severity
Class has too many declared members	Reports the classes that have too many properties or methods.	Disabled
Complex class should be refactored	Reports the classes that are too complex. Class complexity is evaluated based on three metrics: TCC (Tight class cohesion) — the measure of class cohesiveness (more is better). WMC (Weighted Method count) — the sum of cyclomatic complexities for all methods in a class (less is better). ATFD (Access to foreign data) — the number of properties from another class that are accessed in the current class (less is better).	Disabled
Complex function should be refactored	Reports the functions or methods that are too complex. Complexity is evaluated based on four metrics: Lines of code — the number of code lines in a function/method (less is better) Maximum Nesting depth — the maximum number of nested statements in a function/method body (less is better) Cyclomatic complexity — the function/method cyclomatic complexity (less is better) Number of variables — the number of variables used in function/method body	Disabled
Function has too high cyclomatic complexity	Reports the methods that have high cyclomatic complexity and can probably be simplified. See Cyclomatic complexity (wikipedia.org) for details.	Disabled
Halstead metric	Reports the methods with high Halstead Complexity metric. See Halstead measure (wikipedia.org) for details.	Disabled
LCOM metric	Reports the classes that have high Lack of Cohesion metric value, which represents the degree of cohesiveness of a class. It uses class dependency graph components for class cohesiveness measure (M. Hitz and B. Montazeri definition of LCOM metric)	Disabled
Member can be pulled up	Reports the class methods and properties that should be pulled up to the parent class or interface.	Disabled
Method has Feature Envy on another class	Reports the "Feature Envy" code smell. Feature envy is defined as occurring when a method calls methods on another class more times than on the source class. It often indicates that the intended functionality is located in the wrong class. Calls to library classes, parent classes, and contained or containing classes are not counted by this inspection.	Disabled

PHPDoc

Inspection	Description	Default Severity
Inappropriate @inheritDoc usage	Reports inappropriate `@inheritDoc` usages: On non-class members On class members without any super members having a doc comment.	Weak warning
PHPDoc comment matches function/method signature	Reports the parameters' names and types in a PHPDoc comment that do not match the ones in the function/method declaration.	Weak warning
Redundant @throws tag(s)	Reports the `@throws` tags for exceptions that are not thrown by the function/method. The exception classes added to the Unchecked Exceptions list under Settings/Preferences \| PHP \| Analysis are excluded from the inspection scope.	Weak warning
Redundant @var tag	Reports the `@var` tags for variables whose type is already inferred from source code.	Weak warning
Redundant PHPDoc comment	Reports the PHPDoc comments that contain only the information already provided in declarations.	No highlighting, only fix
Return type in PHPDoc comment does not match the actual return type	Reports the return types in PHPDoc comments that do not match the actual return type of a function.	Weak warning
Type already exists in PHPDoc tag	Reports duplicate types in PHPDoc comments.	Weak warning
Type doesn't match property's declared type	Reports the properties' types in PHPDoc `@var` tags that do not match the declared type of a property.	Weak warning

Last modified: 28 March 2022