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

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Browser/OS: Firefox 133 on Linux

View result in a separate tab

Test name	Executions per second
split separator	4479038.0 Ops/sec
split regex	2484541.2 Ops/sec

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

Related benchmarks:

String split separator vs regex (version: 0)

Comparing performance of: split separator vs split regex

Created: 2 years ago by: Guest

Jump to the latest result

split separator

split regex

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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