Using a string provides more information to help diagnose the failure or the assertion reason.

Example:

  void foo(List<Integer> myList) {
    assert myList.isEmpty() : false;
  }

Use the Only warn when the assert message type is 'boolean' or 'java.lang.Boolean' option to only warn when the assert message type is boolean or java.lang.Boolean. A boolean detail message is unlikely to provide additional information about an assertion failure and could result from a mistakenly entered : instead of &.