Comparison between ?? and a orDefault method

main.dart

void main() {
  final String name = "Adam";

  print("=== ?? ===");
  // does not execute defaultValue()
  print(name ?? defaultValue());

  print("=== orDefault ===");
  // executes defaultValue()
  print(name.orDefault(defaultValue()));
}

String defaultValue() {
  print("execute defaultValue()");
  return "Charles";
}

extension Ext<T> on T {
  T orDefault(T defaultValue) {
    if (this == null) return defaultValue;
    return this;
  }
}