Object-Oriented JavaScript - Third Edition

ES6 object methods

ES6 introduces a few static helper methods for objects. Object.assign is a helper method that replaces popular mixins to perform a shallow copy of an object.

Copy properties using Object.assign

This method is used to copy properties of the target object into the source object. In other words, this method merges the source object with the target object and modifies the target object:

    let a = {} 
    Object.assign(a, { age: 25 }) 
    console.log(a)  //{"age":25} 

The first parameter to Object.assign is the target on which source properties are copied. The same target object is returned to the caller. Existing properties are overwritten, while properties that aren't part of the source object are ignored:

 let a = {age : 23, gender: "male"} Object.assign(a, ...