Code Inspection: Method can be made 'static'

Reports the methods that don't use any instance references and thus may be converted to static methods.

Static methods normally belong to utility classes and are accessed in the context of a class rather than an object. In the following example, the foo method does not use any instance references, and can therefore be declared as static.

class A {
    public function foo() {
        return true;
    }
    public function bar() {
        echo $this->foo();
    }
}
$a = new A;
$a->foo();

class A {
    public static function foo() {
        return true;
    }
    public function bar() {
        echo A::foo();
    }
}
$a = new A;
A::foo();