javascript how to copy an object code example

Example 1: copy object javascript

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

Example 2: copy object javascript

// es6
const obj = {name: 'john', surname: 'smith'};
const objCopy = {...obj};

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: javascript clone object

var sheep={"height":20,"name":"Melvin"};
var clonedSheep=JSON.parse(JSON.stringify(sheep));

//note: cloning like this will not work with some complex objects such as:  Date(), undefined, Infinity
// For complex objects try: lodash's cloneDeep() method or angularJS angular.copy() method

Example 5: best way to clone an object in javascript

const person = {
    firstName: 'John',
    lastName: 'Doe'
};


// using spread ...
let p1 = {
    ...person
};

// using  Object.assign() method
let p2 = Object.assign({}, person);

// using JSON
let p3 = JSON.parse(JSON.stringify(person));

Example 6: 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;
}