Benchmark: Array.reduce vs for loop vs Array.forEach vs Array.forIn

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 doLoop(pArray) {
	var accum = 0;
	for(var intCtr=0; intCtr<pArray.length; intCtr++) {
		accum += pArray[intCtr];
	}
	return accum;
}
function doForIn(pArray) {
	var accum = 0;
	for(let item in pArray) {
		accum++;
	}
	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 = doLoop(arrRandom);
forEach
var forEachResult=0 forEachResult = doForEach(arrRandom)
for in
var forInResult=0 forInResult = doForIn(arrRandom)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
for loop
forEach
for in

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

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Let's break down what's being tested on the provided JSON and explain the different approaches, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark tests four different ways to sum 1000 random numbers using JavaScript:

1. `Array.reduce()`: Using the `reduce()` method with a callback function to accumulate the sum.
2. `for loop`: A traditional for loop to iterate through the array and add each number to a running total.
3. `Array.forEach()`: Using the `forEach()` method to iterate through the array and add each number to a running total.
4. `for...in`: Using the `for...in` loop to iterate through the array's properties (which in this case are the numbers) and add them to a running total.

**Library Used**

None of the test cases use any external libraries. All functions (`doRedeuce`, `doLoop`, `doForEach`, and `doForIn`) are defined directly within the benchmark script.

**Special JS Features or Syntax**

* `Array.prototype.reduce()`: This method was introduced in ECMAScript 2015 (ES6) and provides a concise way to reduce an array to a single value.
* `Array.prototype.forEach()`: This method was also introduced in ES6 and allows iterating over an array without having to specify the index of each element.
* `for...in` loop: While not as commonly used, this loop is still supported in modern browsers.

**Approaches Comparison**

Here's a brief comparison of the four approaches:

1. **Array.reduce()**: Pros:
	* Concise and expressive syntax
	* Easy to read and maintain
	* Works well for reducing arrays to single values
Cons:
	* May not be as efficient as traditional loops, especially for large arrays
2. **For loop**: Pros:
	* Efficient and fast
	* Works well for large arrays or complex calculations
Cons:
	* Can be verbose and harder to read
3. **Array.forEach()**: Pros:
	* Easy to use and concise
	* Works well for iterating over arrays without modifying them
Cons:
	* May not be as efficient as traditional loops, especially for large arrays
4. **For...in** loop: Pros:
	* Can be used for non-array iterations (e.g., objects)
Cons:
	* May not be as efficient or expressive as other approaches

**Other Considerations**

* The benchmark script assumes that the input array `arrRandom` is generated randomly, which may affect the performance results.
* The benchmark does not account for any potential side effects or modifications to the original array during the execution of each function.

**Alternatives**

If you want to test different approaches, you could consider adding additional functions, such as:

* Using a different iteration method (e.g., `Array.prototype.map()`, `for...of` loop)
* Implementing custom iterators or generators
* Using external libraries or frameworks that provide optimized iteration methods

Keep in mind that each approach has its trade-offs and may be better suited for specific use cases.

Related benchmarks:

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

A test summing 1000 random numbers, 1 - 10000

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

Created: 4 years ago by: Guest

Jump to the latest result

reduce

for loop

forEach

for in

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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