instanceof运算符

The JavaScript instanceof operator returns true if the first operand is an instance of the object passed on the right, or one of its ancestors in its prototype chain.

如果第一个操作数是在右侧传递的对象的实例或其原型链中的祖先之一，则JavaScript instanceof运算符将返回true。

In this example you can see that the myCar object, of class Fiesta, responds true to instanceof Fiesta, and also responds true to instanceOf Car, because Fiesta extends Car:

在此示例中，您可以看到Fiesta类的myCar对象对Fiesta的instanceof Fiesta响应为true，并且对instanceOf Car响应为true，因为Fiesta扩展了Car：

class Car {}class Fiesta extends Car {}const myCar = new Fiesta()myCar instanceof Fiesta //truemyCar instanceof Car //true

翻译自:

instanceof运算符