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

I have tow classes:

class A {
name: string;
age: number;

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

class B extends A {

}


Also i have an object where i want to use instances of these classes as keys:

const storage: Storage = {};


So it will look like this:

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.'


And then i want to differ value by keys, like:

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');
}
})


How should looks like Storage interface, because in typescript

Storage

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

const storage: Array<[A, string]>

storage.push([a, 'What are...']);

storage

1 Answer
1

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

No, not with object literals.

However, you can use a Map instead:

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

Map

Map

A

B

Map

Map

new Map<K, V>()

Map

Map

Map

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