Benchmark: regex vs. split().slice().join()

Script Preparation code:

var times = ['12:45:55.434542', '10:48:97jggg', '9:20:55.434542', '11:45', '12:45:55 12:30']

Tests:

regex
times.forEach(time => console.log(/\d+:\d+/.exec(time).shift()));
split().slice().join()
times.forEach(time => console.log(time.split(':').slice(0, 2).join(':')));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex
split().slice().join()

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Windows

View result in a separate tab

Test name	Executions per second
regex	12074.1 Ops/sec
split().slice().join()	10509.9 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, compared, and their pros and cons.

**Benchmark Definition**

The benchmark is called "regex vs. split().slice().join()" and it compares two approaches to parse a specific format of time strings: using regular expressions (`/\\d+:\\d+/`) or splitting and joining the string.

**Script Preparation Code**

The script preparation code defines an array `times` containing various time strings in the format "HH:MM", where each string may contain invalid characters (e.g., "10:48:97jggg").

**Html Preparation Code**

There is no HTML preparation code, which means that this benchmark is purely a JavaScript performance test and doesn't rely on any specific HTML structure or content.

**Individual Test Cases**

There are two individual test cases:

1. **"regex"`**: This test case uses regular expressions to extract the hour and minute parts of each time string.
2. **"split().slice().join()"`**: This test case splits the time string into parts using `:` as a delimiter, takes only the first two elements (hour and minute), and then joins them back together with `:` in between.

**Pros and Cons**

1. **Regular Expressions (`/\\d+:\\d+/`)**
	* Pros:
		+ Can handle various formats of time strings.
		+ Portable across different platforms.
	* Cons:
		+ May be slower due to the complexity of regular expressions.
		+ Requires a dedicated regex engine (e.g., JavaScript's built-in `exec()` method).
2. **Split().slice().join()**
	* Pros:
		+ Generally faster since it involves simple string manipulation.
		+ Doesn't require a dedicated regex engine.
	* Cons:
		+ May not handle all possible time formats.

**Library**

The `RegExp` object is used in the regular expression test case, which provides a way to search for patterns in strings. The `exec()` method returns an array containing match results.

**Special JavaScript Feature/Syntax**

There doesn't appear to be any special JavaScript features or syntax being used in this benchmark. Both approaches use standard JavaScript concepts and methods.

**Other Alternatives**

If you were to replace the regular expressions with a different approach, some alternatives could include:

1. **String manipulation libraries**: Using a library like `moment.js` for time parsing might provide better performance and flexibility.
2. **Custom parsing functions**: Creating a custom function to parse the time string might offer more control over the parsing process and potentially better performance.

However, without knowing the specific requirements of your project or the constraints of the benchmark, it's difficult to recommend an alternative approach that would significantly improve performance or accuracy.

Related benchmarks:

regex vs. split().slice().join() (version: 0)

Comparing performance of: regex vs split().slice().join()

Created: 2 years ago by: Guest

Jump to the latest result

regex

split().slice().join()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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