Js Array Methods — Free Javascript Tutorial

TL;DR: Learn Js Array Methods in Javascript with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.

Js Array Methods in Javascript

Modern JavaScript array methods process arrays without for loops. They are cleaner, more readable, and chainable.

map() transforms each element and returns a NEW array. filter() keeps only elements that pass a test. reduce() accumulates all elements into a single value.

find() returns the first matching element. some() checks if ANY element passes. every() checks if ALL pass. forEach() runs a function on each (no return).

These methods can be chained: students.filter(s => s.marks >= 60).map(s => s.name) — get names of passing students.

const nums = [1, 2, 3, 4, 5];

nums.map(n => n * 2)          // [2, 4, 6, 8, 10]
nums.filter(n => n % 2 === 0) // [2, 4]
nums.reduce((sum, n) => sum + n, 0) // 15
nums.find(n => n > 3)         // 4
nums.some(n => n > 4)         // true
nums.every(n => n > 0)        // true

Learn Js Array Methods step by step with Syllab's free interactive Javascript tutorial — runnable code examples, practice exercises and instant AI feedback, all free with no signup. Explore the full Javascript course →