Benchmark: Array filter vs. for loop - with for in222222sgdsgdsg

Script Preparation code:

var arr = ['dd', 'aa', 'dd', 'xx', 'dd', 'aa', 'as', 'ds', 'dd'], farr;

Tests:

Filter
farr = arr.filter(function(item) { return /dd/.test(item) }).length;
For
let count = 0; for (var i=0,len=arr.length;i<len;i++) { if (/dd/.test(arr[i])) count++; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Filter
For

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Filter	4366358.5 Ops/sec
For	1703294.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**What is being tested?**

The benchmark is testing two approaches to filter an array of strings: using the `filter()` method and using a traditional `for` loop with a regular expression (`/dd/.test(item)`).

**Options compared:**

1. **Filter()**: This method creates a new array containing only the elements that pass the test implemented by the provided function.
2. **For loop with regular expressions**: This approach uses a `for` loop to iterate over the array, and for each element, it checks if the regular expression matches using `/dd/.test(item)`.

**Pros and Cons:**

1. **Filter()**:
	* Pros: Efficient, concise, and easy to read.
	* Cons: Creates a new array, which can be memory-intensive for large datasets.
2. **For loop with regular expressions**:
	* Pros: Can be faster for very large arrays since it doesn't create a new array, and it allows for more control over the iteration process.
	* Cons: Can be slower due to the overhead of the `for` loop, and the regular expression matching can be computationally expensive.

**Other considerations:**

1. **Regular expressions**: The benchmark uses the `/dd/.test(item)` syntax, which is a common way to use regular expressions in JavaScript. However, there are other ways to write regular expressions, such as using a function with `RegExp.test()` or using the `String.prototype.matchAll()` method.
2. **Browser differences**: The benchmark results show different execution counts for each test case on Chrome 114 running on a Mac OS X 10.15.7 system. This highlights the importance of considering browser-specific optimizations and potential differences in performance.

**Library usage:**

There is no explicit library mentioned in the benchmark, but the `filter()` method and regular expressions are built-in JavaScript features.

**Special JS feature or syntax:**

None mentioned.

Now, let's discuss alternative approaches to this benchmark:

1. **Using other array methods**: Instead of `filter()`, you could also use `map()`, `every()`, or `some()` to filter the array.
2. **Using `forEach()` with a callback function**: You can use the `forEach()` method with an arrow function as a callback to iterate over the array and perform the filtering.
3. **Using a custom iterator**: If you're familiar with iterators, you could create a custom iterator that filters the array on-the-fly without creating a new one.

Keep in mind that these alternative approaches may have different performance characteristics or trade-offs, so it's essential to experiment and measure their results for your specific use case.

Related benchmarks:

Array filter vs. for loop - with for in222222sgdsgdsg (version: 0)

Comparing performance of: Filter vs For

Created: one year ago by: Guest

Jump to the latest result

Filter

For

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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