Benchmark: String split separator vs regex

HTML Preparation code:

<script>
  var str = 'charlie alpha foxtrot beta gamma delta omega iota kappa lambda mu nu xi omicron theta eta zeta',
      delim = ', ';
</script>

Tests:

split separator
str.split(' ')
split regex
str.split(/\s/)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
split separator
split regex

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain the provided benchmark and its test cases.

**What is being tested?**

The benchmark measures the performance difference between two approaches for splitting a string:

1. Using the `split()` method with a fixed separator (space characters).
2. Using the `split()` method with a regular expression that matches one or more whitespace characters (`\\s`).

**Options compared:**

* **Fixed separator:** The test splits the input string using the space character as the delimiter.
* **Regular expression:** The test uses a regular expression to match and split the input string into substrings.

**Pros and Cons of each approach:**

* **Fixed separator (split()):**
	+ Pros:
		- Simple and easy to understand.
		- Fast, as it directly accesses the separator characters in the string.
	+ Cons:
		- May not work correctly for strings with non-space delimiters (e.g., tabs or newline characters).
		- Can be slower than regular expressions if the separator is a common character like space.
* **Regular expression (split(regex)):**
	+ Pros:
		- More flexible and can handle multiple delimiter types, including whitespace characters, tabs, newlines, etc.
		- Can be faster for large strings with non-space delimiters.
	+ Cons:
		- More complex and harder to understand than fixed separators.
		- May be slower due to the overhead of compiling and executing regular expressions.

**Library usage:**

In this benchmark, no external libraries are used other than built-in JavaScript methods (`split()`).

**Special JS feature or syntax:**

There is no special JavaScript feature or syntax being tested in this benchmark. The code only uses standard JavaScript constructs.

**Other alternatives:**

If you need to split strings with different delimiter types (e.g., multiple whitespace characters, tabs, newlines), regular expressions might not be the best approach. You can consider using other approaches like:

* Using `split()` with an array of delimiters or a regex pattern that matches all possible delimiter types.
* Implementing custom string splitting logic in your code.
* Utilizing third-party libraries or tools designed for text processing and parsing.

Keep in mind that the specific choice of approach depends on the requirements and constraints of your project.

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/21A329 Twitter for iPhone/10.7

Browser/OS: Mobile Safari 17 on iOS 17.0

View result in a separate tab

Test name	Executions per second
split separator	9573406.0 Ops/sec
split regex	2113741.0 Ops/sec

Related benchmarks:

String split separator vs regex (version: 0)

Comparing performance of: split separator vs split regex

Created: one year ago by: Guest

Jump to the latest result

split separator

split regex

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):