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);

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: 16 days 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

Test name	Executions per second
for	16943146.0 Ops/sec
foreach	6822418.0 Ops/sec
some	5898811.5 Ops/sec
every	9791800.0 Ops/sec
for..of	949913.6 Ops/sec
map	5838782.0 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.

Related benchmarks:

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: 5 years ago by: Guest

Jump to the latest result

for

foreach

some

every

for..of

map

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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