Unused lambda expression

Reports lambda expressions that are neither invoked nor assigned.

A lambda expression that is neither invoked nor assigned to a variable has no effect on program execution and is likely unintentional.

Example:

  fun foo() {
    {} // Warning: Lambda expression is never invoked
  }

After the quick fix is applied:

  fun foo() {
    run {} // Lambda is now invoked via the 'run' function
  }

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.

UnusedLambdaExpression

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 | Kotlin | Probable bugs

Inspection ID: UnusedLambdaExpression

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 UnusedLambdaExpression

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