How to append something to an array?

Answer 1

I think it's worth mentioning that push can be called with multiple arguments, which will be appended to the array in order. For example:

var arr = ['first'];
arr.push('second', 'third');
console.log(arr);

As a result of this you can use push.apply to append an array to another array like so:

var arr = ['first'];
arr.push('second', 'third');
arr.push.apply(arr, ['forth', 'fifth']);
console.log(arr);

Annotated ES5 has more info on exactly what push and apply do.

2016 update: with spread, you don't need that apply anymore, like:

var arr = ['first'];
arr.push('second', 'third');

arr.push(...['fourth', 'fifth']);
console.log(arr) ;

Answer 2

The push() method adds new items to the end of an array, and returns the new length. Example:

var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.push("Kiwi");

// The result of fruits will be:
Banana, Orange, Apple, Mango, Kiwi

The exact answer to your question is already answered, but let's look at some other ways to add items to an array.

The unshift() method adds new items to the beginning of an array, and returns the new length. Example:

var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.unshift("Lemon", "Pineapple");

// The result of fruits will be:
Lemon, Pineapple, Banana, Orange, Apple, Mango

And lastly, the concat() method is used to join two or more arrays. Example:

var fruits = ["Banana", "Orange"];
var moreFruits = ["Apple", "Mango", "Lemon"];
var allFruits = fruits.concat(moreFruits);

// The values of the children array will be:
Banana, Orange, Apple, Mango, Lemon

Answer 3

Append a value to an array

Since Array.prototype.push adds one or more elements to the end of an array and returns the new length of the array, sometimes we want just to get the new up-to-date array so we can do something like so:

const arr = [1, 2, 3];
const val = 4;

arr.concat([val]); // [1, 2, 3, 4]

Or just:

[...arr, val] // [1, 2, 3, 4]

Answer 4

push() adds a new element to the end of an array.
pop() removes an element from the end of an array.

To append an object (such as a string or number) to an array use -
array.push(toAppend);

Answer 5

you can do it using new javascript Es 6 feature :

// initialize array

var arr = [
    "Hi",
    "Hello",
    "Bangladesh"
];

// append new value to the array

arr= [...arr , "Feni"];

// or you can put a variable value

var testValue = "Cool";

arr = [...arr , testValue ];

console.log(arr); 

// final output  [ 'Hi', 'Hello', 'Bangladesh', 'Feni', 'Cool' ]

Answer 6

If arr is an array, and val is the value you wish to add use:

arr.push(val);

E.g.

var arr = ['a', 'b', 'c'];
arr.push('d');
console.log(arr);