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

Script Preparation code:

var array = Array.from(Array(500).keys())

Tests:

for
let greatThan1 = false; for (var i = 0; i < array.length; i++) { array[i]; if(array[i]>1) greatThan1 = true }
foreach
let greatThan1 = false; array.forEach(function(i) { array[i]; if(i>1) greatThan1 = true });
some
array.some(function(i) { return i>1; });
for..of
let greatThan1 = false; for (var i of array) { array[i]; if(array[i]>1) greatThan1 = true }
map
array.map(a => a);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

The provided benchmark definition is testing the performance of different loop constructs in JavaScript: `for`, `forEach`, `some`, and `every`. The test cases are designed to compare the execution speed of these loops on a large array of 500 elements.

**Loop Constructs Compared**

1. **`for` Loop**: This is a traditional loop construct that uses an incrementing counter variable to iterate over the array.
2. **`forEach` Loop**: This is a more modern loop construct introduced in ECMAScript 5, which iterates over an array using a callback function.
3. **`some` Loop**: This is a method that returns `true` if at least one element of the array satisfies the condition inside the callback function.
4. **`every` Loop**: This is a method that returns `true` if all elements of the array satisfy the condition inside the callback function.
5. **`for..of` Loop**: This is another modern loop construct introduced in ECMAScript 2015, which iterates over an array using a foreach-like syntax.

**Pros and Cons**

*   **Traditional `for` Loop**:
    *   Pros: More control over iteration variables, better performance in some cases.
    *   Cons: Can be verbose, requires manual indexing.
*   **`forEach` Loop**:
    *   Pros: Modern, readable, and concise syntax, easy to use with callback functions.
    *   Cons: May have overhead due to function calls, not suitable for all iteration use cases.
*   **`some` Loop** and **`every` Loop**:
    *   Pros: Compact syntax, convenient for conditional iteration.
    *   Cons: Limited control over iteration variables, may have performance implications depending on the condition.

**Library Used**

None explicitly mentioned in the provided benchmark definition. However, it's likely that a JavaScript engine or browser is used to execute these loops, as indicated by the `Browser` and `DevicePlatform` fields in the latest benchmark result.

**Special JS Features/Syntax**

*   **`for..of` Loop**: Introduced in ECMAScript 2015, this loop construct allows iterating over arrays using a foreach-like syntax. It was designed to replace traditional `forEach` loops.
*   **Arrow Functions**: Used extensively in the benchmark definition for the `map`, `some`, and `every` methods.

**Other Considerations**

The performance of these loops can vary depending on factors such as:

*   Array size and distribution
*   Condition complexity inside the callback function or loop body
*   Browser/JavaScript engine optimizations

**Alternative Loop Constructs**

Some other JavaScript loop constructs include:

*   **`while` Loop**: A traditional loop construct that uses a conditional statement to control iteration.
*   **`do...while` Loop**: An iterative loop construct that executes at least once before the condition is checked.

It's worth noting that this benchmark definition only tests specific loop constructs and may not be representative of all JavaScript use cases.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.54 Safari/537.36

Browser/OS: Chrome 101 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
for	17850.8 Ops/sec
foreach	44918.8 Ops/sec
some	23479004.0 Ops/sec
for..of	26556.4 Ops/sec
map	1081095.0 Ops/sec

Related benchmarks:

for vs foreach vs some vs every vs for..of vs map for check condition (version: 3)

Compare loop performance

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

Created: 2 years ago by: Registered User

Jump to the latest result

for

foreach

some

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 28 days ago):