Overwritten Map, Set, or array element

Reports code that overwrites a Map key, a Set element, or an array element in a sequence of add/put calls or using a Java 9 factory method like Set.of (which will result in runtime exception).

This usually occurs due to a copy-paste error.

Example:

  map.put("A", 1);
  map.put("B", 2);
  map.put("C", 3);
  map.put("D", 4);
  map.put("A", 5); // duplicating key "A", overwrites the previously written entry

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.

OverwrittenKey

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 | Probable bugs

New in 2017.3

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 OverwrittenKey

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