javascript insert element into array 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: array insertion javascript

Array.prototype.insert = function ( index, item ) {
    this.splice( index, 0, item );
};

Example 3: how to insert a value into an array javascript

var list = ["foo", "bar"];


list.push("baz");


["foo", "bar", "baz"] // result

Example 4: javascript add array to array at index

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

Example 5: js add array items to array

var arrayA = [1, 2];
var arrayB = [3, 4];
var newArray = arrayA.concat(arrayB);

Example 6: set element at index javascript array and create new array

const items = [1, 2, 3, 4, 5]

const insert = (arr, index, newItem) => [
  // part of the array before the specified index
  ...arr.slice(0, index),
  // inserted item
  newItem,
  // part of the array after the specified index
  ...arr.slice(index)
]

const result = insert(items, 1, 10)

console.log(result)
// [1, 10, 2, 3, 4, 5]