Array.prototype.forEach()
Executes a provided function once for each array element.
Syntax
arr.forEach(callback, thisArg)Parameters
| Name | Type | Required | Description |
|---|---|---|---|
callback | Function | Yes | Function called for each element with (element, index, array). Its return value is ignored. |
thisArg | any | No | Value to use as `this` when executing the callback. |
Returns
undefined — Always returns undefined.
Examples
['a', 'b', 'c'].forEach((v, i) => console.log(i, v));
Output
0 a
1 b
2 c
let sum = 0;
[1, 2, 3].forEach(n => { sum += n; });
console.log(sum);
Output
6
Notes
Cannot be stopped early with `break` or `return`; use a `for...of` loop or
`some`/`every` for early exit. Skips empty slots in sparse arrays. Does not
build a new array - use `map` for that.
Browser & runtime support
| Environment | Since version |
|---|---|
| chrome | 1.0 |
| firefox | 1.5 |
| safari | 3.0 |
| edge | 12 |
| node | 0.10 |