Benchmark: fork of for vs foreach vs some vs every vs for..of vs map

Script Preparation code:

var array = new Array(28837600);

Tests:

for
for (var i = 0; i < array.length; i++) { array[i]; }
foreach
array.forEach(function(i) { array[i]; });
some
array.some(function(i) { array[i]; });
every
array.every(function(i) { array[i]; });
for..of
for (var i of array) { array[i]; }
map
array.map(a => a);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
foreach
some
every
for..of
map

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 116 on Android

View result in a separate tab

Test name	Executions per second
for	0.2 Ops/sec
foreach	9.1 Ops/sec
some	7.0 Ops/sec
every	9.1 Ops/sec
for..of	0.2 Ops/sec
map	4.9 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks, comparing the performance of different loop constructs in JavaScript.

The benchmark definition json file defines a set of test cases that compare six different loop constructs:

1. Traditional `for` loop
2. `forEach`
3. `some`
4. `every`
5. `for..of` (introduced in ECMAScript 2015)
6. `map`

These loops are designed to iterate over an array of length 28,864,000.

**Loop Options and Their Pros/Cons**

1. **Traditional `for` loop**: This is a straightforward loop that uses an index variable `i` to access each element in the array.
	* Pros: Easy to understand and implement, good for small arrays.
	* Cons: Can be slow for large arrays due to the overhead of incrementing the index variable.
2. **`forEach`**: This loop iterates over the elements of an array using a callback function.
	* Pros: Convenient and easy to use, no need to worry about indices.
	* Cons: Can lead to slower performance due to the overhead of creating a new function object.
3. **`some`**: This loop returns `true` as soon as it finds an element in the array that satisfies a given condition.
	* Pros: More efficient than traditional `for` loops for arrays with multiple false positives, but can be slow if no such elements are found.
	* Cons: Requires careful consideration of the stopping criterion to avoid unnecessary iterations.
4. **`every`**: This loop returns `true` only if all elements in the array satisfy a given condition.
	* Pros: Similar to `some`, but with an additional requirement for consecutive true values, which can improve performance.
	* Cons: Still requires careful consideration of the stopping criterion.
5. **`for..of`**: This loop is similar to traditional `for` loops, but uses a more modern syntax that eliminates the need to manually increment the index variable.
	* Pros: More readable and concise than traditional `for` loops, good for small arrays.
	* Cons: Can be slower due to the overhead of creating a new iterator object.
6. **`map`**: This loop returns a new array with the results of applying a given transformation function to each element in the original array.
	* Pros: Convenient and easy to use, can simplify complex data transformations.
	* Cons: Creates an additional memory allocation for the resulting array, which can be expensive.

**Library Usage**

In this benchmark, none of the loops use external libraries. However, some JavaScript engines may optimize or implement custom optimizations that are not explicitly shown here.

**Special JS Features or Syntax**

The `for..of` loop and `map` function utilize modern JavaScript features:

* **`for..of`**: Introduced in ECMAScript 2015 as a new loop construct that eliminates the need to manually increment an index variable. It uses an iterator object to traverse the array elements.
	+ Pros: More readable and concise than traditional `for` loops, good for small arrays.
	+ Cons: Can be slower due to the overhead of creating a new iterator object.

**Alternatives**

Other alternatives for iterating over arrays include:

* **Array.prototype.reduce()**: A method that applies a reduction function to all elements in an array and returns a single value. While it can be used as a loop substitute, its performance characteristics are different from traditional loops.
* **Set or Map data structures**: For specific use cases, such as iterating over unique values or key-value pairs, using Set or Map data structures might provide better performance.

Keep in mind that the choice of iteration method depends on the specific problem requirements and performance constraints.

Related benchmarks:

fork of for vs foreach vs some vs every vs for..of vs map (version: 0)

Compare loop performance

Comparing performance of: for vs foreach vs some vs every vs for..of vs map

Created: one year ago by: Guest

Jump to the latest result

for

foreach

some

every

for..of

map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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