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Showing content from https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Symbol/hasInstance below:

Symbol.hasInstance - JavaScript | MDN

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Symbol.hasInstance 用于判断某对象是否为某构造器的实例。因此你可以用它自定义 instanceof 操作符在某个类上的行为。

class Array1 {
  static [Symbol.hasInstance](instance) {
    return Array.isArray(instance);
  }
}

console.log([] instanceof Array1);
// Expected output: true

你可实现一个自定义的instanceof 行为，例如：

class MyArray {
  static [Symbol.hasInstance](instance) {
    return Array.isArray(instance);
  }
}
console.log([] instanceof MyArray); // true

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