Concatenation with empty string

Reports empty string operands in string concatenations. Concatenation with the empty string can be used to convert non-String objects or primitives into Strings, but it can be clearer to use a String.valueOf() method call.

A quick-fix is suggested to simplify the concatenation.

Example:

  void foo(int x, int y) {
    String s = "" + x + " ; " + y;
  }

After the quick-fix is applied:

  void foo(int x, int y) {
    String s = x + " ; " + y;
  }

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

ConcatenationWithEmptyString

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Java | Verbose or redundant code constructs

Use the Report only where empty strings can be removed without other changes option to ignore cases cases where removing the empty string will require adding a String.valueOf() conversion of another operand.

Inspection options

Here you can find the description of settings available for the Concatenation with empty string inspection, and the reference of their default values.

Report only where empty strings can be removed without other changes: Default: Selected

Inspection Details
By default bundled with:	IntelliJ IDEA 2024.2, Qodana for JVM 2024.2,
Can be installed with plugin:	Java, 242.22892

Last modified: 11 September 2024