Javascript 在 ES6 中,如何检查对象的类?
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In ES6, how do you check the class of an object?
提问by Ivan
In the ES6, if I make a class and create an object of that class, how do I check that the object is that class?
在 ES6 中,如果我创建一个类并创建该类的对象,我如何检查该对象是否是该类?
I can't just use typeofbecause the objects are still "object". Do I just compare constructors?
我不能只是使用,typeof因为对象仍然是"object". 我只是比较构造函数吗?
Example:
例子:
class Person {
constructor() {}
}
var person = new Person();
if ( /* what do I put here to check if person is a Person? */ ) {
// do stuff
}
回答by Eric
Can't you do person instanceof Person?
你不能person instanceof Person吗?
Comparing constructors alone won't work for subclasses
单独比较构造函数不适用于子类
回答by galarant
Just a word of caution, the use of instanceofseems prone to failure for literals of built-in JS classes (e.g. String, Number, etc). In these cases it might be safer to use typeofas follows:
谨慎的只是一个字,使用的instanceof似乎容易出现故障的内置JS类(如文字String,Number等等)。在这些情况下,使用typeof以下方法可能更安全:
typeof("foo") === "string";
typeof("foo") === "string";
Refer to this threadfor more info.
有关更多信息,请参阅此线程。

