JavaScript Array Methods

Learn about the array methods in JavaScript

📄️ concat()

concat() populates a new array with the concatenation of its calling array and its arguments.

📄️ every()

every() returns true if all its calling array's items pass its function argument's test. Otherwise, it returns false.

📄️ filter()

filter() creates a new array that contains all the calling array's elements that passed the test specified by the method's argument.

📄️ find()

find() finds the calling array's element that first passes the test specified by the method's function argument.

📄️ findIndex()

findIndex() finds the index of the calling array's element that first passes the test specified by the method's function argument.

📄️ forEach()

The forEach() method invokes its argument once for each item of an existing array.

📄️ includes()

includes() checks if its calling array includes the method's first argument.

📄️ indexOf()

indexOf() searches its calling array for the first occurrence of the method's string argument.

📄️ join()

join() creates a new string by using a comma, or a user-defined separator, to join the elements of an array object.

📄️ lastIndexOf()

lastIndexOf() searches its calling array for the last occurrence of the method's argument.

📄️ map()

map() creates a new array that contains the result of invoking map()'s function argument on each item of the calling array.

📄️ pop()

JavaScript's pop() method removes and returns its calling array's last item. It does not accept any argument.

📄️ push()

JavaScript's push() method adds its arguments to the end of its calling array and returns the calling array's new length.

📄️ reduce()

Whenever you use reduce() on an array, the method uses its function argument to reduce its calling array's items to a single value.

📄️ reverse()

reverse() reverses an array so that its first item becomes the last and its last element becomes the first.

📄️ shift()

JavaScript's shift() method removes and returns its calling array's first item. It does not accept any argument.

📄️ slice()

JavaScript's slice() method duplicates a specified part of its calling array into a new array—without altering the original array.

📄️ some()

some() returns true if some of its calling array's items pass its function argument's test. Otherwise, it returns false.

📄️ sort()

sort() sorts its calling array's items in ascending (or descending) order and returns the sorted array.

📄️ splice()

JavaScript's splice() method alters its calling array by adding or removing a specific number of items to/from it.

📄️ unshift()

JavaScript's unshift() method adds its arguments to the beginning of its calling array and returns the calling array's new length.