Run results for: Comparison of three map functions

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36

Browser: Chrome 111

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
MAP	141.3 Ops/sec
ARRAY_WITH_NO_LENGTH	63.4 Ops/sec
MAP_HOW_ARRAY_METHOD	83.9 Ops/sec

Script Preparation code:

function map(arr, callback) {
	const _length = arr.length;

	const result = new Array(_length);

	for (let i = 0; i < _length; i++) {
		result[i] = callback(arr[i], i, arr);
	}

	return result;
}

function arrayWithNoLength(arr, callback) {
	const result = [];

	for (let i = 0; i < arr.length; i++) {
		result.push(callback(arr[i], i, arr));
	}

	return result;
}

function mapHowArrayMethod(arr, callback) {
	return arr.map(callback);
}

Tests:

MAP
map(new Array(1000000).fill(1000), (num) => num * 2);
ARRAY_WITH_NO_LENGTH
arrayWithNoLength(new Array(1000000).fill(1000), (num) => num * 2);
MAP_HOW_ARRAY_METHOD
mapHowArrayMethod(new Array(1000000).fill(1000), (num) => num * 2);

Run results for: Comparison of three map functions

There are three map functions. 1. Function with optimizations 2. The most common implementation of map 3. Native map as a function method

MAP

ARRAY_WITH_NO_LENGTH

MAP_HOW_ARRAY_METHOD