javascript add new array element to start of array
var colors = ["white","blue"];
colors.unshift("red"); //add red to beginning of colors
// colors = ["red","white","blue"]
javascript add new array element to start of array
var colors = ["white","blue"];
colors.unshift("red"); //add red to beginning of colors
// colors = ["red","white","blue"]
unshift
//see https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/Array/unshift
const array1 = [1, 2, 3];
console.log(array1.unshift(4, 5));
// expected output: 5
console.log(array1);
// expected output: Array [4, 5, 1, 2, 3]
unshift method in javascript
var name = [ "john" ];
name.unshift( "charlie" );
name.unshift( "joseph", "Jane" );
console.log(name);
//Output will be
[" joseph "," Jane ", " charlie ", " john "]
insert element at beginning of array javascript
// Use unshift method if you don't mind mutating issue
// If you want to avoid mutating issue
const array = [3, 2, 1]
const newFirstElement = 4
const newArray = [newFirstElement].concat(array) // [ 4, 3, 2, 1 ]
console.log(newArray);
shift and unshift js
let cats = ['Bob', 'Willy', 'Mini'];
cats.shift(); // ['Willy', 'Mini']
let cats = ['Bob'];
cats.unshift('Willy'); // ['Willy', 'Bob']
cats.unshift('Puff', 'George'); // ['Puff', 'George', 'Willy', 'Bob']
unshift javascript
/*The unshift() adds method elements to the beginning, and push() method
adds elements to the end of an array.*/
let twentyThree = 'XXIII';
let romanNumerals = ['XXI', 'XXII'];
romanNumerals.unshift('XIX', 'XX');
// now equals ['XIX', 'XX', 'XXI', 'XXII']
romanNumerals.push(twentyThree);
// now equals ['XIX', 'XX', 'XXI', 'XXII', 'XXIII']
Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us