JS-063
Educational JavaScript lesson graphic for map(): Learn to create a new array by transforming every element with map()
Beginner6 min~6 min read#array#map#arrays

map()

Transform every element

Goal

Learn to create a new array by transforming every element with map().

Explanation

  • map() iterates over every element in an array.
  • A function runs for each element.
  • The results are collected in a new array.
  • The original array does not change.
  • map() is often used to prepare data.

Analogy

Imagine a conveyor belt. Regular apples go in, and peeled apples come out the other side. Every element undergoes the same transformation.

Code

const numbers = [1, 2, 3];

const doubled = numbers.map(
  n => n * 2
);

console.log(doubled);

Result: [2, 4, 6]

Common mistake

Beginners often think map() changes the original array. In fact, it creates a new one.

Remember

  • ✦ map() creates a new array.
  • ✦ The original array does not change.
  • ✦ Every element undergoes a transformation.

Quick Quiz

What does [1, 2, 3].map(n => n * 2) return?

Resources