JavaScript Array flat()

Definition and Usage

flat() Method used to concatenate the elements of the sub-array to a new array.

See Also:

Array map() Method

Array flatMap() Method

Array filter() Method

Array forEach() Method

Example

Example 1

Create a new array and concatenate the elements of the sub-array:

const myArr = [[1,2],[3,4],[5,6]];
const newArr = myArr.flat();

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Example 2

For multi-layered nested arrays, you can specify the expansion depth:

const myArr = [1, 2, [3, [4, 5, 6], 7], 8];
const newArr = myArr.flat(2);

Try It Yourself

Syntax

array.flat(depth)

Parameter

Return Value

Browser Support

Since January 2020, all modern browsers support JavaScript arrays flat() Method: