Benchmark: Array.reduce vs for loop vs Array.forEach vs for of loop 2

Script Preparation code:

//Create an array of 1000 random intergers between 1 and 10000
var arrRandom = [];
for(var intCtr=0; intCtr<1000; intCtr++) {
  arrRandom.push(Math.floor(Math.random() * Math.floor(10000)));
}

function reduceCallback(accum, curr) {
	return accum+curr;
}

function doRedeuce(pArray) {
	return pArray.reduce(reduceCallback);
}
function doForLoop(pArray) {
	var accum = 0;
	var arrLength = pArray.length;
	for(var intCtr=0; intCtr<arrLength; intCtr++) {
		accum += pArray[intCtr];
	}
	return accum;
}
function doForOfLoop(pArray) {
	var accum = 0;
	for(var value of pArray) {
		accum += value;
	}
	return accum;
}
function doForEach(pArray) {
	var accum = 0;
	pArray.forEach(function(item) {
		accum += item;
	});
}

Tests:

reduce
var redeuceResult=0; redeuceResult = doRedeuce(arrRandom);
for loop
var loopResult=0; loopResult = doForLoop(arrRandom);
forEach
var forEachResult=0 forEachResult = doForEach(arrRandom)
for of loop
var forOfResult=0 forOfResult = doForOfLoop(arrRandom)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
for loop
forEach
for of loop

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its options.

**Benchmark Overview**

The benchmark is designed to compare the performance of four different approaches for summing up an array of random numbers:

1. `Array.prototype.reduce()`
2. Traditional `for` loop
3. `Array.prototype.forEach()` (note: this method does not return the accumulated value, but we're using it as if it did)
4. `for...of` loop

**Options Compared**

The benchmark compares the performance of each option by executing them multiple times and measuring their execution time per second.

* `reduce()`: uses an arrow function to specify the callback function for the reduction
* Traditional `for` loop: uses a traditional `for` loop with a counter variable
* `forEach()` (as if it returned the accumulated value): uses the `forEach()` method without modifying it, as if it were returning the accumulated value
* `for...of` loop: uses a `for...of` loop to iterate over the array

**Pros and Cons of Each Approach**

1. `reduce()`:
	* Pros: concise and expressive code, avoids explicit loops
	* Cons: might be less efficient due to additional overhead
2. Traditional `for` loop:
	* Pros: efficient and well-established pattern, easy to understand
	* Cons: more verbose than `reduce()` or `forEach()`
3. `forEach()` (as if it returned the accumulated value):
	* Pros: similar to `reduce()` in syntax and intent, avoids explicit loops
	* Cons: not a standard method of `Array.prototype.forEach()`, might be less efficient due to additional overhead
4. `for...of` loop:
	* Pros: concise and expressive code, easy to understand
	* Cons: relatively new feature, might not be supported by older browsers or environments

**Library Usage**

In this benchmark, the `reduce()` method uses an arrow function to specify the callback function for the reduction.

**Special JS Feature/Syntax**

The benchmark does not use any special JavaScript features or syntax that are not widely supported (e.g., ES6+ syntax). However, it's worth noting that the `for...of` loop is a relatively new feature that was introduced in ECMAScript 2015.

**Alternative Approaches**

Other alternatives for summing up an array of numbers could include:

* Using `Array.prototype.map()` and then calling `reduce()` on the resulting mapped array
* Using a `while` loop or other iterative approach
* Using a functional programming library like Lodash

These alternative approaches might have different performance characteristics, syntax requirements, and ease of use compared to the options tested in this benchmark.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36

Browser/OS: Chrome 70 on Windows

View result in a separate tab

Test name	Executions per second
reduce	44698.5 Ops/sec
for loop	656834.1 Ops/sec
forEach	384501.5 Ops/sec
for of loop	557607.2 Ops/sec

Related benchmarks:

Array.reduce vs for loop vs Array.forEach vs for of loop 2 (version: 0)

A test summing 1000 random numbers, 1 - 10000

Comparing performance of: reduce vs for loop vs forEach vs for of loop

Created: 5 years ago by: Guest

Jump to the latest result

reduce

for loop

forEach

for of loop

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):