flutter - = 和 : in named parameters 之间的 Dart 区别

Question

class Student {
  String name;
  int age;
  int id;

  Student({this.name, this.id = 101, this.age: 20});
}

上述构造函数中的 = 和 : 有什么区别？两者似乎都做同样的工作。

Answer 1

来自文档:

Deprecation note: Old code might use a colon (:) instead of = to set default values of named parameters. The reason is that originally, only : was supported for named parameters. That support is likely to be deprecated, so we recommend that you use = to specify default values.

来源: https://dart.dev/guides/language/language-tour