Cast conflicts with 'instanceof'

Reports type cast expressions that are preceded by an instanceof check for a different type.

Although this might be intended, such a construct is most likely an error, and will result in a java.lang.ClassCastException at runtime.

Example:

  class Main {
    int whenCharSequenceCastToNumber(Object o){
      if (o instanceof CharSequence) {
        return ((Number) o).intValue();
      }
      return 0;
    }

    int earlyReturnWhenNotCharSequence(Object o){
      if (!(o instanceof CharSequence)) return 0;
      return ((Number)o).intValue();
    }
  }

Locating this inspection

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CastConflictsWithInstanceof

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Settings or Preferences | Editor | Inspections | Java | Probable bugs

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