javascript array shift unshift code example

Example 1: 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"]

Example 2: unshift method in javascript

var name = [ "john" ];
name.unshift( "charlie" );
name.unshift( "joseph", "Jane" );
console.log(name);

//Output will be
[" joseph "," Jane ", " charlie ", " john "]

Example 3: prepend to js array

var a = [1, 2, 3, 4];
a.unshift(0);
a; // => [0, 1, 2, 3, 4]

Example 4: 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']