dart - 下面代码的输出应该是什么？这个对吗？

Question

如果我没记错的话，这段代码应该打印出来：

 "dart.core.dynamic"

但打印以下内容：

 "dynamic"

我的代码：

    import 'dart:mirrors';

    main() {
      var mirror = reflectType(dynamic);
      var symbol = mirror.qualifiedName;
      print(symbol); // -> "dynamic"
    }

Answer 1

I think "dynamic" is a perfectly good result.

The usual qualified name prefixes the type name with the declaring library's name. You are expecting it to prefix "dart.core", which is the name of the "dart:core" library, but "dynamic" is not declared in that library (https://api.dartlang.org/docs/channels/stable/latest/dart_core.html), so that would be the wrong prefix to use.

The "dynamic" type is a synthetic type that is not declared in any library - there is no "class" or "typedef" declaration that could declare a type behaving as "dynamic" does. It's only specified by the specification and implemented internally in the compilers and runtime systems.

Having a qualified name with no prefix makes perfect sense in this case. It's the same you get for "void".

Answer 2

这是答案如何在 Dart 中从 Type 实例中获取限定名称？

你忘记了

 Symbol symbol = mirror.qualifiedName;
 String qualifiedName = MirrorSystem.getName(symbol);