map() method returns a new array populated with the results of calling a provided function on every element in the calling array.

syntax ↴

map(callbackFn) A function to execute for each element in the array ↴

function is called with the following arguments ↴

map(function(element, index, array), thisArg) ↴

callback function allows access to each element, the index, and the original array itself.

thisArg (optional). Value to use as this when executing callbackFn. By default, it is undefined.

map() method returns a new array with each element being the result of the callback function.

map() method does not execute the function for empty elements.

map() method does not change the original array.

A sparse array remains sparse after map()

The indices of empty slots are still empty in the returned array, and the callback function won't be called on them.

map() method similar to iterating over an array using a for loop ↴

const myArray = [1, 4, 9, 16];

for (let i = 0; i < myArray.length; i++) {

  myArray[i] = myArray[i] * 2;

} myArray returns ↴

[2, 8, 18, 32]

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