Benchmark: Array.some vs for loop

Script Preparation code:

var array = new Array(1000).fill('');
array = array.map((tem, idx) => idx)
var result = false;

Tests:

for
for (var i = 0; i < array.length; i++) { if (array[i] === 888) { result = true; break; } }
some
result = array.some(function(i) { return array[i] === 888; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
some

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:141.0) Gecko/20100101 Firefox/141.0

Browser/OS: Firefox 141 on Linux

View result in a separate tab

Test name	Executions per second
for	1702392.5 Ops/sec
some	123752.9 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition JSON**

The benchmark definition is comparing the performance of two loop-based approaches: `for` loop and `Array.some()` method.

**Script Preparation Code**

The script preparation code creates an array of 1000 empty strings, converts it to an indexed array by mapping each element to its index using the arrow function syntax `(tem, idx) => idx`, and then sets a variable `result` to `false`.

**Html Preparation Code (null)**

There is no HTML preparation code provided.

**Test Cases**

The benchmark consists of two individual test cases:

1. **"for"`**
	* The test case defines a `for` loop that iterates over the array, and checks if each element is equal to 888. If it finds a match, it sets `result` to `true` and breaks out of the loop.
2. **"some"`**
	* The test case uses the `Array.some()` method to iterate over the array and checks if any element is equal to 888. It returns `true` as soon as it finds a match.

**What's being tested?**

The benchmark is testing the performance of two different loop-based approaches:

1. **`for` loop**: The test case measures the execution time of a traditional `for` loop that iterates over the array.
2. **`Array.some()` method**: The test case measures the execution time of using the `Array.some()` method to check for any element in the array.

**Pros and Cons**

* **`for` loop**:
	+ Pros: More control over iteration, easier to optimize performance-critical loops.
	+ Cons: Can be slower due to overhead of incrementing the loop variable and checking conditions inside the loop.
* **`Array.some()` method**:
	+ Pros: Shorter code, more concise, and often faster since it's optimized for iterating over arrays.
	+ Cons: Less control over iteration, can be slower if not properly optimized.

**Library**

The `Array.some()` method is a built-in JavaScript function that's part of the ECMAScript standard. It's implemented in various browsers and Node.js environments.

**Special JS feature/Syntax**

This benchmark uses a relatively modern JavaScript feature: arrow functions (`(tem, idx) => idx`). These are used to define small, concise functions without declaring `var`, `let`, or `const` variables.

**Other alternatives**

If you wanted to test the performance of other loop-based approaches, some alternatives could include:

* Using `forEach()` instead of `for`
* Using a custom iterator function
* Using a library like Lodash's `each` method

However, these alternatives might not be as straightforward or well-supported by modern browsers and Node.js environments.

**Other considerations**

When interpreting benchmark results, keep in mind the following:

* The test environment (e.g., browser, Node.js version) can affect performance.
* The input data size and distribution can impact performance.
* Other factors like caching, memory allocation, and garbage collection might influence execution times.

These factors are not directly addressed by this benchmark, but they're essential to consider when comparing the performance of different JavaScript implementations.

Related benchmarks:

Array.some vs for loop (version: 4)

Compare loop performance

Comparing performance of: for vs some

Created: 4 years ago by: Registered User

Jump to the latest result

for

some

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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