How to add new array element at the start of an array in javascript?

I have already created a array dynamically using Ajax,  but now when i am getting new values to server, sometime i need to add that array on first position based on requirements, so how can i add a new element of an array to first position using javascript(preferred) or jQuery?

Asked by:- jaiprakash
: 3723 At:- 11/20/2017 7:11:13 AM
javascript add element to beginning of array javascript javascript array insert at index

3 Answers
profileImage Answered by:- Sam

Unshift and Shift are the functions which can be used to add or remove elements from the array starting point, while Push and pop are the functions which is used to add element or remove relement at the end of the array

so basically what you need is

var a = [12, 24, 50, 100]; //this is your array
a.unshift(11); // add element add the start of an array
console.log(a); // this will be your result [11,12, 24, 50, 100]

here is a simple diagram created by me


hope the aboave helps to understand functions to add or remove elements from arrays in javascript

At:- 11/21/2017 1:09:51 PM Updated at:- 12/24/2022 7:40:22 AM
great explanation using the image, thanks 0
By : jaiprakash - at :- 11/22/2017 7:26:20 AM

profileImage Answered by:- neena

The above answer works well, but I think it is better to use Javascript .splice() method, which is used to add/remove items from an array, here is the example of it.

var arr = [12, 30, 34, 55];
arr.splice(0, 0, 11);

Output of above will give arr value as below


If you want to understand array.splice method, here is it's syntax

array.splice(PositionToAddRemoveItems, HowManyItemsToRemove, Item1ToAdd, ....., ItemXtoAdd)

So basically, that's why we used arr.splice(0, 0, 11);

to add item a 0th (1st) position,

0 elements to remove

and added new item with value '11'.

At:- 6/13/2021 5:55:25 PM

profileImage Answered by:- jon

You can also use concat() in javascript to add new array element at first position and to avoid mutating array object, here is an example

const array = [2,3,4]

const addFirstElement = 1

const newArray = [addFirstElement].concat(array) 

console.log(newArray); // [ 1,2,3,4]

You can also use concat() to append item at an end of an array.

const array = [1,2,3,4]

const newLastElement = 5;

const newArray = array.concat(newLastElement);

console.log(newArray); // [ 1,2,3,4,5]


At:- 12/24/2022 2:47:11 PM

Login/Register to answer
Register directly by posting answer/details

Full Name *

Email *

By posting your answer you agree on privacy policy & terms of use