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

Script Preparation code:

var array = new Array(100);

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);

Historical Performance Data aggregated from 123 community runs

Desktop Results:

Chrome 96 runs

foreach

5.5M/s

every

5.4M/s

some

5.2M/s

map

4.7M/s

for..of

244K/s

for

156K/s

Fastest: foreach (35.4x faster)

View exact numbers

✓ foreach: 5,527,424 ops/sec
• every: 5,364,880 ops/sec
• some: 5,201,094 ops/sec
• map: 4,659,824 ops/sec
• for..of: 243,773 ops/sec
• for: 156,270 ops/sec

Firefox 22 runs

for

18.4M/s

some

10.1M/s

every

10.1M/s

foreach

7.7M/s

map

7.3M/s

for..of

1.5M/s

Fastest: for (12.5x faster)

View exact numbers

✓ for: 18,360,446 ops/sec
• some: 10,139,382 ops/sec
• every: 10,138,623 ops/sec
• foreach: 7,698,841 ops/sec
• map: 7,310,288 ops/sec
• for..of: 1,465,579 ops/sec

Mobile Results:

Chrome 5 runs

every

1.9M/s

some

1.8M/s

foreach

1.8M/s

map

1.3M/s

for..of

110K/s

for

69K/s

Fastest: every (26.8x faster)

View exact numbers

✓ every: 1,853,852 ops/sec
• some: 1,841,575 ops/sec
• foreach: 1,824,015 ops/sec
• map: 1,301,608 ops/sec
• for..of: 110,401 ops/sec
• for: 69,297 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

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: 3 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:151.0) Gecko/20100101 Firefox/151.0

Browser/OS: Firefox 151 on Windows

View result in a separate tab

for

16.9M/s

every

9.8M/s

foreach

6.8M/s

some

5.9M/s

map

5.8M/s

for..of

950K/s

View exact numbers

Test name	Executions per second
✓ for	16,943,146 Ops/sec
every	9,791,800 Ops/sec
foreach	6,822,418 Ops/sec
some	5,898,812 Ops/sec
map	5,838,782 Ops/sec
for..of	949,914 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided benchmark compares the performance of six different loop constructs in JavaScript: `for`, `foreach`, `some`, `every`, `for..of`, and `map`. The goal is to determine which approach is the most efficient.

**Options Compared**

The options compared are:

1. **Traditional `for` loop**: This is a general-purpose loop that uses an index variable to iterate over an array.
2. **`foreach` loop**: This loop iterates over an array using a callback function, similar to `forEach`.
3. **`some` loop**: This loop returns true as soon as the condition is met, and stops iterating over the array.
4. **`every` loop**: This loop returns true only if all elements in the array meet the condition, and stops iterating after checking all elements.
5. **`for..of` loop**: This is a newer loop construct that iterates over arrays using a `for...of` statement, similar to traditional `for` loops but with more concise syntax.
6. **`map` function**: This function applies a transformation to each element in the array and returns a new array.

**Pros and Cons of Each Approach**

1. **Traditional `for` loop**:
	* Pros: Simple, well-established, and widely supported.
	* Cons: Can be verbose, especially for large arrays or complex iterations.
2. **`foreach` loop**:
	* Pros: Concise syntax, easy to read, and suitable for simple loops.
	* Cons: Less control over iteration flow compared to traditional `for`.
3. **`some` loop**:
	* Pros: Returns early when condition is met, reducing unnecessary iterations.
	* Cons: May not be intuitive for developers without experience with this construct.
4. **`every` loop**:
	* Pros: Similar to `some`, returns early when all elements meet the condition.
	* Cons: Less control over iteration flow compared to traditional `for`.
5. **`for..of` loop**:
	* Pros: Concise syntax, easy to read, and suitable for simple loops.
	* Cons: Limited support in older browsers or environments.
6. **`map` function**:
	* Pros: Applies transformation to each element, creating a new array with the results.
	* Cons: May not be suitable for simple iteration tasks, can create unnecessary memory allocation.

**Library Usage**

None of the provided benchmark cases use any external libraries.

**Special JS Features or Syntax**

The `for..of` loop is a relatively new feature in JavaScript (introduced in ECMAScript 2015), which allows iterating over arrays using a concise syntax. The `map`, `some`, and `every` functions are also part of the standard library.

**Alternatives**

If you're interested in exploring alternative approaches, consider:

1. **Generators**: Similar to traditional loops but with more control over iteration flow.
2. **Async loops**: Loops that handle asynchronous iterations using callbacks or promises.
3. **Closures**: Functions that use variables from the surrounding scope, which can be useful for complex loop logic.

In summary, each approach has its pros and cons, and the choice ultimately depends on the specific requirements of your project, such as performance, readability, and maintainability.

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

Compare loop performance

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

Created: 5 years ago by: Guest

Go to the latest result

for

foreach

some

every

for..of

map

Historical Performance Data aggregated from 123 community runs

Desktop Results:

Chrome 96 runs

Firefox 22 runs

Mobile Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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

Compare loop performance

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

Created: 5 years ago by: Guest

Go to the latest result

for

foreach

some

every

for..of

map

Historical Performance Data aggregated from 123 community runs

Desktop Results:

Chrome 96 runs

Firefox 22 runs

Mobile Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

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