JavaScript Array flatMap()

Example

const myArr = [1, 2, 3, 4, 5, 6];
const newArr = myArr.flatMap((x) => x * 2);
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Description

The flatMap() method maps all array elements and creates a new flat array.

flatMap() creates a new array from calling a function for every array element.

flatMap() does not execute the function for empty elements.

flatMap() does not change the original array.


Syntax

array.flatMap(function(currentValue, index, arr), thisValue)

Parameters

Parameter Description
function() Required.
A function to be run for each array element.
currentValue Required.
The value of the current element.
index Optional.
The index of the current element.
arr Optional.
The array of the current element.
thisValue Optional.
Default value undefined.
A value passed to the function to be used as its this value.

Return Value

Type Description
An arrayAn array with the elements as a result of a callback function and then flattened.


Browser Support

JavaScript Array flatMap() is supported in all modern browsers since January 2020:

Chrome 69 Edge 79 Firefox 62 Safari 12 Opera 56
Sep 2018 Jan 2020 Sep 2018 Sep 2018 Sep 2018


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