Attaching a common method to multiple object literals

Question

I have several objects constructed by object literals:

let obj1={
    list: [],
    a() {},
    b() {},
};
let obj2={
    list: [],
    c() {},
    d() {},
};

Now I want to attach a common method to all objects, say

const f=()=>console.log(this.list);

But If I do

obj1.f=f; obj2.f=f;

And try to run it, it will give undefined.

How to do this so that this can correspond to the object?

You could also extract a method: `const f = { f(){ console.log(this.list); } }.f;`, then assign `[ obj1, obj2 ].forEach((obj) => obj.f = f)`. — Sebastian Simon, Oct 09 '19 at 10:57
@インターミディエイト Yes, [it does work](https://i.stack.imgur.com/eUjSC.png). Please don’t radically change the question like this. — Sebastian Simon, Oct 09 '19 at 10:59

score 1 · Answer 1 · answered Oct 09 '19 at 10:59

You need to have a non-arrow function and then it will work as below:

let obj1={
    list: [],
    a() {},
    b() {},
};
let obj2={
    list: [],
    c() {},
    d() {},
};

const f=function() {console.log(this.list);}
obj1.f=f; 
obj2.f=f;

console.log(obj1);
console.log(obj2)

Attaching a common method to multiple object literals

1 Answers1