Benchmark: for vs foreach vs some

Script Preparation code:

var array = new Array(100);

Tests:

for
var i; for (i = 0; i < array.length; i++) { array[i]; }
foreach
array.forEach(function(item, index) { array[i]; });
some
array.some(function(item, index) { array[i]; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
foreach
some

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its options.

**Benchmark Definition**

The benchmark compares the performance of three loop constructs in JavaScript: `for`, `foreach`, and `some`. The script preparation code creates an array with 100 elements, which is used as input for each test case.

**Options being compared**

1. **`for` loop**: This loop uses a traditional `for` loop with an incrementing index variable (`i`) to iterate over the array.
2. **`forEach` loop**: This loop uses the `Array.prototype.forEach()` method, which executes a callback function for each element in the array.
3. **`some` loop**: This loop uses the `Array.prototype.some()` method, which returns `true` as soon as the callback function returns `true`, and skips subsequent iterations.

**Pros and Cons of each approach**

1. **`for` loop**:
	* Pros: Easy to understand and write, allows for fine-grained control over iteration.
	* Cons: Can be slower than other options due to unnecessary increments, may have performance issues with large arrays.
2. **`forEach` loop**:
	* Pros: Simple and concise syntax, doesn't require manual index management.
	* Cons: May incur additional overhead due to callback function execution, can be less performant than `for` loops for certain iterations.
3. **`some` loop**:
	* Pros: Can skip unnecessary iterations, potentially more efficient for arrays with fewer elements.
	* Cons: May have higher overhead due to early returns and potential caching issues, less intuitive syntax compared to other options.

**Library used**

None explicitly mentioned in the benchmark definition, but `Array.prototype.forEach()` and `Array.prototype.some()` are part of the JavaScript standard library.

**Special JS feature/syntax**

The benchmark uses ES5 syntax for the loops (e.g., `array.length`, `for` loop syntax) but does not specify any modern features like arrow functions or let/const blocks. However, it does use a callback function in each iteration, which is a common pattern in JavaScript.

**Other alternatives**

If you're looking for alternative loop constructs, consider:

1. **`map()`**: Similar to `forEach`, but returns an array of results instead of nothing.
2. **`reduce()`**: Reduces the array to a single value by applying a callback function to each element.
3. **`every()`** and **`some()`**: These methods return a boolean indicating whether all or any elements in the array pass a given test.

Keep in mind that each alternative has its own trade-offs and use cases, so be sure to evaluate them based on your specific performance requirements and coding style preferences.

Latest run results:

Run details: (Test run date: 8 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:48.0) Gecko/20100101 Firefox/48.0

Browser/OS: Firefox 48 on Mac OS X 10.10

View result in a separate tab

Test name	Executions per second
for	1551012.5 Ops/sec
foreach	3986104.5 Ops/sec
some	3928042.0 Ops/sec

Related benchmarks:

for vs foreach vs some (version: 0)

Compare loop performance

Comparing performance of: for vs foreach vs some

Created: 8 years ago by: Guest

Jump to the latest result

for

foreach

some

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):