Benchmark: Comparison of three map functions

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);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
MAP
ARRAY_WITH_NO_LENGTH
MAP_HOW_ARRAY_METHOD

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

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/OS: Chrome 111 on Windows

View result in a separate tab

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

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and benchmark setup.

**Benchmark Definition**

The benchmark is designed to compare three different approaches to implementing the `map` function in JavaScript:

1. **Function with optimizations**: This implementation uses a custom `map` function that takes an array, callback function, and returns a new array with the results of applying the callback to each element.
2. **The most common implementation of map**: This is likely a reference implementation, which is not shown in the provided JSON. It's assumed to be a widely-used and well-tested implementation.
3. **Native map as a function method**: This approach uses the built-in `map` method, which is a part of the JavaScript language.

**Options Compared**

The benchmark compares the performance of these three approaches:

* Function with optimizations
* The most common implementation of map (reference implementation)
* Native map as a function method

**Pros and Cons**

1. **Function with optimizations**: This approach allows for customization and control over the mapping process. However, it may require more manual memory management and error handling.
2. **The most common implementation of map**: This is likely to be a widely-used and well-tested implementation, but its performance may vary depending on the specific JavaScript engine or version used.
3. **Native map as a function method**: This approach provides the best performance and convenience, as it's a built-in part of the language. However, its behavior may not be explicitly documented in all cases.

**Library and Purpose**

None of the provided implementations use any external libraries. They are custom implementations of the `map` function.

**Special JS Feature or Syntax**

The benchmark uses a special JavaScript feature: array methods (`map`, `forEach`, etc.). These methods were introduced in ECMAScript 2015 (ES6) and provide a concise way to iterate over arrays.

**Other Alternatives**

If you're looking for alternative implementations of the `map` function, you could consider:

* Using a library like Lodash or Ramda, which provide utility functions for working with arrays.
* Implementing a custom iterator using the `Symbol.iterator` and `next()` methods.
* Using a different programming paradigm, such as functional programming with immutable data structures.

Keep in mind that these alternatives may have different performance characteristics and use cases compared to the benchmarked implementations.

Related benchmarks:

Comparison of three map functions (version: 0)

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

Comparing performance of: MAP vs ARRAY_WITH_NO_LENGTH vs MAP_HOW_ARRAY_METHOD

Created: 2 years ago by: Registered User

Jump to the latest result

MAP

ARRAY_WITH_NO_LENGTH

MAP_HOW_ARRAY_METHOD

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):