How to add a property at the beginning of an object in javascript

Question

I have

var obj = {'b': 2, 'c': 3}; 

And i would like to add a property at the beginning (not at the end) of that object:

var obj = {'a': 1, 'b': 2, 'c': 3}; 

Is there a clean way to do that?

Answer 1

You can also use Object.assign() in ES6 (ES2015+).

let obj = {'b': 2, 'c': 3}; const returnedTarget = Object.assign({a: 1}, obj);  // Object {a: 1, b: 2, c: 3} 

Answer 2

These days you could use the cool spread operator (...) in ES6 (ES2015+), try out the following:

const obj = {'b': 2, 'c': 3};       const startAdded = {'a':1 , ...obj};  console.log(startAdded);    const endAdded = {...obj, 'd':4};  console.log(endAdded);

Might help someone out there in the wild :)