forEach()

Syntax

arr.forEach((item, index, array) => { });

Examples

const fruits = ["apple", "banana", "cherry"];

fruits.forEach(fruit => {
  console.log(fruit);
});
// apple, banana, cherry

const scores = [85, 92, 78];

scores.forEach((score, index, array) => {
  console.log(`Score ${index + 1} of ${array.length}: ${score}`);
});
// Score 1 of 3: 85
// Score 2 of 3: 92
// Score 3 of 3: 78

// Wrong intent - forEach() returns undefined, this does nothing useful
const numbers = [1, 2, 3];
const result = numbers.forEach(n => n * 2);
console.log(result); // undefined

// Correct - use map() when you need the transformed values back
const doubled = numbers.map(n => n * 2);
console.log(doubled); // [2, 4, 6]

Best practices

• Use forEach() only for side effects (logging, DOM updates, pushing to an external array) - never expect a return value from it
• Use map() instead of forEach() whenever you actually need a transformed array back
• Remember you cannot break or continue out of a forEach() loop - use a regular for or for...of loop if you need that control
• Avoid using forEach() with async/await callbacks expecting sequential execution - it does not wait for promises between iterations

At a glance

Purpose

Application logic and interaction

File extension

.js · .mjs

Runs in

Browsers and JavaScript runtimes

Usually used with

HTML, CSS and Web APIs

Specifications & further reading

• ECMAScript specification

Related JavaScript documentation