JavaScript Array Methods

Beginner

6 min read

Updated: Nov 2026

39 method guides

Method index

Index

About This Index

This page is the JavaScript Array Methods index for the tutorial track. Each row links to a full guide with syntax, examples, and FAQs.

Learn what an Array is on /js/array. Use this page when you need a specific API such as push(), map(), or filter().

Beginner path.

Start with push(), map(), filter(), and find()—then browse search, reduce, and the methods that edit the array in place.

Syntax

How to Call an Array Method

Instance methods use a dot; static helpers use Array:

JavaScript

const colors = ["red", "green"];
const nums = [1, 2, 3];

// Instance (Array.prototype)
colors.push("blue");          // mutates colors
nums.map(function (n) {       // new array
  return n * 2;
});
nums.filter(function (n) {
  return n > 1;
});

// Static (on Array)
Array.isArray(colors);        // true
Array.from("hi");             // ["h", "i"]
Array.of(1, 2, 3);            // [1, 2, 3]

Browse

JavaScript Array Methods Table

All method guides in this JavaScript tutorial series (39 tutorials).

Getting Started

6 methods

Essential methods for reading, adding, and removing elements.

Method	Description	Tutorial
`at()`	Retrieves an element at a specified index, including negative offsets from the end.	Open
`push()`	Adds one or more elements to the end and returns the new length.	Open
`pop()`	Removes and returns the last element, mutating the array.	Open
`shift()`	Removes and returns the first element, shifting others down.	Open
`unshift()`	Adds elements to the beginning and returns the new length.	Open
`slice()`	Returns a shallow copy of a portion without mutating the original.	Open

Search & Test

9 methods

Find values and check whether elements match a condition.

Method	Description	Tutorial
`includes()`	Checks whether an array contains a value; returns true or false.	Open
`indexOf()`	Returns the first index of a value, or -1 if not found.	Open
`lastIndexOf()`	Returns the last index of a value, searching backward.	Open
`find()`	Returns the first element that satisfies a testing function.	Open
`findIndex()`	Returns the index of the first element that passes a test.	Open
`findLast()`	Returns the last element that satisfies a testing function.	Open
`findLastIndex()`	Returns the index of the last element that passes a test.	Open
`some()`	Returns true if at least one element passes a test function.	Open
`every()`	Tests whether all elements pass a callback; returns true or false.	Open

Transform & Aggregate

6 methods

Map, filter, flatten, and reduce data into new shapes.

Method	Description	Tutorial
`map()`	Creates a new array by transforming each element with a callback.	Open
`filter()`	Creates a new array with elements that pass a test function.	Open
`flat()`	Flattens nested arrays into a single-level array.	Open
`flatMap()`	Maps each element then flattens the result by one level.	Open
`reduce()`	Reduces the array to a single value by applying a callback left to right.	Open
`reduceRight()`	Like reduce(), but processes elements from right to left.	Open

In-Place Changes

5 methods

Methods that modify the original array directly.

Method	Description	Tutorial
`splice()`	Adds, removes, or replaces elements at a given index in place.	Open
`sort()`	Sorts elements in place using an optional compare function.	Open
`reverse()`	Reverses element order in place and returns the same array.	Open
`fill()`	Fills all or part of an array with a static value, mutating the array.	Open
`copyWithin()`	Copies a sequence of elements within the array to another index in place.	Open

Iteration

4 methods

Loop over elements or expose iterators.

Method	Description	Tutorial
`forEach()`	Runs a callback for each element; does not return a new array.	Open
`entries()`	Returns an iterator of [index, value] pairs for each element.	Open
`keys()`	Returns an iterator of index keys for the array.	Open
`values()`	Returns an iterator of the array element values.	Open

Combine & Immutable Updates

2 methods

Merge arrays or return updated copies without mutation.

Method	Description	Tutorial
`concat()`	Combines two or more arrays into a new array without mutating the originals.	Open
`with()`	Returns a new array with one index replaced; does not mutate the original.	Open

String Conversion

4 methods

Turn arrays into readable strings.

Method	Description	Tutorial
`join()`	Joins all elements into a string with an optional separator.	Open
`toString()`	Returns a comma-separated string of the array elements.	Open
`toLocaleString()`	Returns a locale-aware string representing the array.	Open
`valueOf()`	Returns the primitive value of the array (the array itself).	Open

Static Methods

3 methods

Array constructor helpers — not called on an instance.

Method	Description	Tutorial
`Array.from()`	Creates an array from an iterable or array-like object.	Open
`Array.isArray()`	Returns true if the value is an array, false otherwise.	Open
`Array.of()`	Creates a new array from the arguments you pass in.	Open

Frequently Asked Questions

What are JavaScript Array methods?

Array methods are functions on Array.prototype such as push(), map(), filter(), and find(). A few helpers are static and live on Array itself: Array.from(), Array.isArray(), and Array.of().

How is this page different from /js/array?

The Array page teaches what an array is—literals, indexes, length, and the difference between push() and map(). This Methods index lists every method tutorial so you can open map(), filter(), and the rest.

How do I call an Array method?

Instance methods use a dot: colors.push("gold"), nums.map(function (n) { return n * 2; }). Static methods use Array: Array.isArray(value), Array.from("hi").

Which methods change the original array?

push(), pop(), shift(), unshift(), splice(), sort(), reverse(), and fill() change the same array. map(), filter(), slice(), concat(), and with() return a new array.

Where should I start?

If you are new, read JavaScript Array first. Then open push(), map(), filter(), and find() from the tables below.

Start with push()

Open the add-to-end guide—syntax, examples, and FAQs.

push() tutorial →

About the author

Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

Experience 12 years building web and cloud systems
Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

AWS Certified Developer – Associate (Credly)

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