String comparison using '==', instead of 'equals()'

Reports code that uses of == or != to compare strings.

These operators determine referential equality instead of comparing content. In most cases, strings should be compared using equals(), which does a character-by-character comparison when the strings are different objects.

Example:

  void foo(String s, String t) {
    final boolean b = t == s;
  }

If t is known to be non-null, then it's safe to apply the "unsafe" quick-fix and get the result similar to the following:

  void foo(String s, String t) {
    final boolean b = t.equals(s);
  }

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.

StringEquality

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

Availability

By default bundled with: IntelliJ IDEA 2024.1, Qodana for JVM 2024.1,
Can be installed with plugin: Java, 241.18072

Last modified: 18 June 2024