问题:

How can I determine whether an object is of a class or not in the Dart language?

I'm looking to do something like the following:

if (someObject.class.toString() == "Num") {
    ...
}

And what is the returned value type? Will it have to be a String?

The mirror library has been up and down and seems to be subject to rapid change right now, as the one thing I did find simply did not work as shown.

回答1:

By using the is and is! operators, like this:
```
if (someObject is T)
```
From the documentation:

The is and is! operators are handy for checking types. The result of obj is T is true if obj implements the interface specified by T. For example, obj is Object is always true.

Using the Mirrors API (see this example):

Expect.equals('T', someObject.simpleName)

回答2:

Recently Object got runtimeType getter. So, now we may not only compare type of object with another type, but actually get the class name of an object. As in:

myObject.runtimeType.toString()

Furthermore, in the current version of Dart, you can now skip toString operation and directly compare runtimeType of object with target type as in