javascript - typescript 中有什么方法可以使用对象作为键吗？

Question

我有两门课:

class A {
  name: string;
  age: number;

  constructor(name: string, age: number) { 
      this.name = name;
      this.age = age;
  }
}

class B extends A {

}

我还有一个对象，我想在其中使用这些类的实例作为键:

const storage: Storage = {};

所以它看起来像这样:

const a = new A('Neo', 25);
const b = new A('Smith', 31);
storage[a] = 'What are you trying to tell me? That I can dodge bullets?';
storage[b] = 'Never send a human to do a machine's job.'

然后我想通过键来区分值，例如:

const keys = Object.keys(storage);
keys.forEach(key => {
  if (key instanceof A) {
    console.log('This is Neo');
  } else if (key instanceof B) {
    console.log('This is Smith');
  }
})

应该看起来像Storage接口(interface)，因为在 typescript 中

An index signature parameter type must be 'string' or 'number'

Answer 1

Is there any way in typescript to use objects as keys?

不，不能使用对象文字。

但是，您可以使用Map相反:

The Map object holds key-value pairs. Any value (both objects and primitive values) may be used as either a key or a value.