Benchmark: for vs forEach - MeasureThat.net

Tests:

for loop

var testArray = [];

for (var i = 1; i <= 100; i++) {
   testArray.push(i);
}

for(var i = 0, length = testArray.length; i < length; i += 1) {
  console.log(testArray[i]);
}

​x
 
var testArray = [];​for (var i = 1; i <= 100; i++) {   testArray.push(i);}​for(var i = 0, length = testArray.length; i < length; i += 1) {  console.log(testArray[i]);}​

forEach

var testArray = [];

for (var i = 1; i <= 100; i++) {
   testArray.push(i);
}

testArray.forEach((item) => {
  console.log(item);
});

 
var testArray = [];​for (var i = 1; i <= 100; i++) {   testArray.push(i);}​testArray.forEach((item) => {  console.log(item);});​

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

Test case name	Result
for loop
forEach

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/69.0.3497.81 Chrome/69.0.3497.81 Safari/537.36

Browser/OS: Chromium 69 on Ubuntu

View result in a separate tab

Test name	Executions per second
for loop	1531.0 Ops/sec
forEach	705.1 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

Let's break down the benchmark and explain what's being tested.

Benchmark Overview

The benchmark is comparing two approaches: for loop and forEach method (also known as Array.prototype.forEach() in JavaScript). The test cases create an array of numbers from 1 to 100, perform some operations on it, and then log each element to the console using either a for loop or the forEach method.

Options Compared

Two options are being compared:

for Loop: A traditional loop that uses a counter variable (i) to iterate over the array elements.
forEach Method: A built-in method that iterates over an array and executes a callback function for each element.

Pros and Cons of Each Approach

`for` Loop

Pros:

Performance: In general, for loops can be faster than forEach methods because they avoid the overhead of function calls and don't require creating an iterator object.
Control: With a for loop, you have more control over the iteration process, such as incrementing the counter variable.

Cons:

Code Complexity: Writing a for loop can be more verbose than using the forEach method.
Error Handling: If the array is empty or contains null/undefined values, the for loop may throw errors.

`forEach` Method

Pros:

Concise Code: Using the forEach method is a concise way to iterate over an array and perform operations on each element.
Easy Error Handling: The forEach method automatically skips null or undefined values in the array.

Cons:

Performance Overhead: Calling the forEach method can introduce some performance overhead due to function call overhead.
Limited Control: With the forEach method, you have less control over the iteration process than with a for loop.

Library and Special JS Features

There are no libraries mentioned in this benchmark. However, if we were to use other JavaScript features, we might consider:

Async/Await: If we were using asynchronous code, async/await syntax would be an alternative way to write loops.
Generators: We could also explore using generators as a more efficient way to iterate over large datasets.

Other Considerations

When writing benchmarks like this one, it's essential to consider the following factors:

Language Features: Be aware of any language features that might affect performance or code complexity, such as type inference, null safety, or caching.
Platform-Specific Optimizations: Some platforms (e.g., WebAssembly) may provide optimizations for certain loops or data structures.
Test Variations: Consider running multiple test variations to account for different scenarios, such as varying array sizes, data distribution, or concurrency levels.

Alternatives

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

Closures: You could use closures (function expressions that capture variables from their scope) to create a custom iterator.
Iterator Protocols: Explore implementing custom iterator protocols for your specific use case.
WebAssembly: Consider optimizing loops or data structures using WebAssembly's low-level abstractions.

Keep in mind that the choice of approach depends on your specific requirements, performance constraints, and personal preferences.

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark is comparing two approaches: `for` loop and `forEach` method (also known as Array.prototype.forEach() in JavaScript). The test cases create an array of numbers from 1 to 100, perform some operations on it, and then log each element to the console using either a `for` loop or the `forEach` method.

**Options Compared**

Two options are being compared:

1. **`for` Loop**: A traditional loop that uses a counter variable (`i`) to iterate over the array elements.
2. **`forEach` Method**: A built-in method that iterates over an array and executes a callback function for each element.

**Pros and Cons of Each Approach**

### `for` Loop

Pros:

* **Performance**: In general, `for` loops can be faster than `forEach` methods because they avoid the overhead of function calls and don't require creating an iterator object.
* **Control**: With a `for` loop, you have more control over the iteration process, such as incrementing the counter variable.

Cons:

* **Code Complexity**: Writing a `for` loop can be more verbose than using the `forEach` method.
* **Error Handling**: If the array is empty or contains null/undefined values, the `for` loop may throw errors.

### `forEach` Method

Pros:

* **Concise Code**: Using the `forEach` method is a concise way to iterate over an array and perform operations on each element.
* **Easy Error Handling**: The `forEach` method automatically skips null or undefined values in the array.

Cons:

* **Performance Overhead**: Calling the `forEach` method can introduce some performance overhead due to function call overhead.
* **Limited Control**: With the `forEach` method, you have less control over the iteration process than with a `for` loop.

**Library and Special JS Features**

There are no libraries mentioned in this benchmark. However, if we were to use other JavaScript features, we might consider:

* **Async/Await**: If we were using asynchronous code, async/await syntax would be an alternative way to write loops.
* **Generators**: We could also explore using generators as a more efficient way to iterate over large datasets.

**Other Considerations**

When writing benchmarks like this one, it's essential to consider the following factors:

* **Language Features**: Be aware of any language features that might affect performance or code complexity, such as type inference, null safety, or caching.
* **Platform-Specific Optimizations**: Some platforms (e.g., WebAssembly) may provide optimizations for certain loops or data structures.
* **Test Variations**: Consider running multiple test variations to account for different scenarios, such as varying array sizes, data distribution, or concurrency levels.

**Alternatives**

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

* **Closures**: You could use closures (function expressions that capture variables from their scope) to create a custom iterator.
* **Iterator Protocols**: Explore implementing custom iterator protocols for your specific use case.
* **WebAssembly**: Consider optimizing loops or data structures using WebAssembly's low-level abstractions.

Keep in mind that the choice of approach depends on your specific requirements, performance constraints, and personal preferences.

Related benchmarks:

for vs forEach (version: 0)

Comparing performance of: for loop vs forEach

Created: 7 years ago by: Guest

Jump to the latest result

for loop

forEach

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

`for` Loop

`forEach` Method

for vs forEach (version: 0)

Comparing performance of: for loop vs forEach

Created: 7 years ago by: Guest

Jump to the latest result

for loop

forEach

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

for Loop

forEach Method

`for` Loop

`forEach` Method