Redundant lambda parameter types

Reports lambda formal parameter types that are redundant because they can be inferred from the context.

Example:

  Map<String, Integer> map = ...
  map.forEach((String s, Integer i) -> log.info(s + "=" + i));

The quick-fix removes the parameter types from the lambda.

  Map<String, Integer> map = ...
  map.forEach((s, i) -> log.info(s + "=" + i));

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.

-RedundantLambdaParameterType

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 | Declaration redundancy

Inspection ID: RedundantLambdaParameterType

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection -RedundantLambdaParameterType

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.3

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.3, Qodana for JVM 2025.3,

Last modified: 03 December 2025