javascript copy object by value code example

Example 1: clone object in js

var student = {name: "Rahul", age: "16", hobby: "football"};

//using ES6
var studentCopy1 = Object.assign({}, student);
//using spread syntax
var studentCopy2 = {...student}; 
//Fast cloning with data loss
var studentCopy3 = JSON.parse(JSON.stringify(student));

Example 2: copy object javascript

var x = {myProp: "value"};
var y = Object.assign({}, x);

Example 3: copy object javascript

var x = {key: 'value'}
var y = JSON.parse(JSON.stringify(x))

//this method actually creates a reference-free version of the object, unlike the other methods
//If you do not use Dates, functions, undefined, regExp or Infinity within your object

Example 4: clone an object javascript

//returns a copy of the object
function clone(obj) {
    if (null == obj || "object" != typeof obj) return obj;
    var copy = obj.constructor();
    for (var attr in obj) {
        if (obj.hasOwnProperty(attr)) copy[attr] = obj[attr];
    }
    return copy;
}