CODEWITHSUNDEEP
javascripttypescript
Mansour Alnasser
Mansour Alnasser

Reputation: 5040

How to override spread operation on a javascript class

I have a Class called Myclass

class Myclass {

 constructor(
    public title: string,
  ) { }

}

in the next example, I want to change the result of the spread operation

let myobject = new Myclass('hello');
console.log({...myobject});

result wanted for example

{
  new_title_name : 'hello'
}

Upvotes: 1

Views: 844

Answers (1)

user15058689
user15058689

Reputation:

This cannot be done. The ECMA-262 specification describes only one way a spread operator can work with objects, with no ability to override it.

If you want to change the set of key-value pairs spread out, you need to provide a different object. Such an object can be generated by a function, method or a property:

class Myclass {
    get data() {
        const result = {};
        for (const k in this) {
            if (typeof this[k] === 'number')
                result[k.toUpperCase()] = this[k];
        }
        return result;
    }
};

const obj = new Myclass();
obj.a = [];
obj.b = null;
obj.c = 13;
obj.d = 'test';
console.info({ ...obj.data });

Upvotes: 2

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