js add to array at index code example

Example 1: javascript insert item into array

var colors=["red","blue"];
var index=1;

//insert "white" at index 1
colors.splice(index, 0, "white");   //colors =  ["red", "white", "blue"]

Example 2: javascript push in specific index

arr.splice(index, 0, item);
//explanation:
inserts "item" at the specified "index",
deleting 0 other items before it

Example 3: javascript Inserting values in between an array

myArray.splice(index, itemsToDelete, item1ToAdd, item2ToAdd, ...)

Example 4: javascript add array to array at index

a1.splice(2, 0, ...a2);

Example 5: add new element by index js

const arr = [ 1, 2, 3, 4 ];
arr[5] = 'Hello, world!';

console.log(arr); // [ 1, 2, 3, 4, <1 empty item>, 'Hello, world!' ]
console.log(arr.length); // 6