Assignment to 'for' loop parameter

Reports assignments to for loop parameters inside the for loop body.

While occasionally intended, this construct can be extremely confusing, and is often the result of a typo.

Example:

  for (value in [1, 2, 3]) {
      value = 4 // warning
  }

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.

GroovyAssignmentToForLoopParameter

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 | Groovy | Assignment issues

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 GroovyAssignmentToForLoopParameter

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

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025