Constructor assigns value to field defined in superclass

Reports assignment to, or modification of fields that are declared in a superclass from within a subclass constructor.

It is considered preferable to initialize the fields of a superclass in its own constructor and delegate to that constructor in a subclass. This will also allow declaring a field final if it isn't changed after the construction.

Example:

  class Super {
    int x;
  }
  class Sub extends Super {
    Sub(int _x) {
      // Warning: x is declared in a superclass
      x = _x;
    }
  }

To avoid the problem, declare a superclass constructor:

  class Super {
    final int x;

    Super(int _x) {
      x = _x;
    }
  }
  class Sub extends Super {
    Sub(int _x) {
      super(_x);
    }
  }

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.

AssignmentToSuperclassField

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 | Assignment issues

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