JavaScript Array Methods

In JavaScript, arrays have a number of built-in methods that allow you to manipulate and operate on the elements of an array. These methods can be used to add, remove, and modify array elements, as well as to perform common operations such as sorting and filtering.

Common Array Methods

Here are some of the most commonly used array methods in JavaScript:

push

Add one or more elements to the end of an array. It returns the new length of the array.

var numbers = [1, 2, 3];
numbers.push(4, 5);
console.log(numbers); // Output: [1, 2, 3, 4, 5]

pop

Remove the last element of an array. It returns the removed element.

var numbers = [1, 2, 3, 4, 5];
numbers.pop();
console.log(numbers); // Output: [1, 2, 3, 4]

shift

Remove the first element of an array. It returns the removed element.

var numbers = [1, 2, 3, 4, 5];
numbers.shift();
console.log(numbers); // Output: [2, 3, 4, 5]

unshift

Add one or more elements to the beginning of an array. It returns the new length of the array.

var numbers = [1, 2, 3];
numbers.unshift(0);
console.log(numbers); // Output: [0, 1, 2, 3]

sort()

Sort the elements of an array in ascending or descending order. It returns the sorted array.

var numbers = [4, 1, 3, 5, 2];
numbers.sort();
console.log(numbers); // Output: [1, 2, 3, 4, 5]

You can also provide a custom sorting function to the sort method, which allows you to control the way the elements are sorted. For example, to sort the array in descending order, you can use the following code:

var numbers = [4, 1, 3, 5, 2];
numbers.sort(function(a, b) {
  return b - a;
});
console.log(numbers); // Output: [5, 4, 3, 2, 1]

filter

Create a new array with only the elements that satisfy a certain condition. It takes a callback function as an argument, which is called for each element of the array, and returns true if the element should be included in the new array, or false if it should be excluded.

var numbers = [1, 2, 3, 4, 5];
var evenNumbers = numbers.filter(function(num) {
  return num % 2 == 0;
});
console.log(evenNumbers); // Output: [2, 4]

List of JavaScript array methods