Benchmark: str.match vs str.Split and for each (regex g flag)

Script Preparation code:

str = "This is a benchmark to test if matching a regex is faster that splitting a string";
regex = /[0-9]/g;
specialCharsList = "!@#$%^&*".split("");

Tests:

regex
regex.test(str)
split and for each
str.split("").forEach(char => { if (specialCharsList.includes(char)) { } });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex
split and for each

Fastest: N/A

Slowest: N/A

Latest run results:

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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 definition, test cases, and results to understand what's being tested.

**Benchmark Definition:**
The main goal of this benchmark is to compare the performance of two approaches:

1. **Regex matching**: Using the `str.match()` method with a regular expression (`regex`) to find all occurrences of specific characters in a string.
2. **String splitting and iterating**: Splitting the input string into an array using the `split()` method, and then iterating over each character in the resulting array to check if it's included in a list of special characters.

**Options Compared:**

* **Regex matching vs String splitting and iteration**
	+ Pros:
		- Regex matching can be more efficient for certain types of text processing, as it allows for pattern matching and handling multiple characters at once.
	+ Cons:
		- Can be slower due to the overhead of compiling regular expressions.
		- May not handle all edge cases correctly.
	+ String splitting and iteration:
		- Pros:
			- Simple and straightforward approach.
			- Easy to understand and debug.
		- Cons:
			- Requires multiple operations (splitting, iterating), which can be slower than a single regex match.

**Special Library or Feature:**
None of the test cases use any special libraries or JavaScript features beyond what's included in the standard library. The benchmark focuses on comparing two basic approaches to text processing.

**Test Users Special JS Feature or Syntax:**
No specialized JavaScript features or syntax are used in this benchmark.

**Other Alternatives:**

* **Using a different regex flavor**: If the regular expression engine being tested is not robust enough, other regex flavors like PCRE (Perl-Compatible Regular Expressions) might be used.
* **Optimizing the regex pattern**: The performance difference between the two approaches could be reduced by optimizing the regex pattern to make it more efficient.

**Benchmark Preparation Code:**
The provided code sets up the test environment:

```javascript
str = "This is a benchmark to test if matching a regex is faster that splitting a string";
regex = /[0-9]/g;
specialCharsList = "!@#$%^&*".split("");
```

This code defines two variables: `str`, which is the input string to be processed, and `regex`, which contains the regular expression pattern.

**Individual Test Cases:**

1. **Regex Matching (Test Name: "regex")**
	+ This test case uses the `str.match()` method with the `regex` variable as an argument.
2. **String Splitting and Iteration (Test Name: "split and for each")**
	+ This test case uses the `split()` method to split the input string into an array, and then iterates over each character in the resulting array using a `for...of` loop.

**Latest Benchmark Results:**

The provided results show the performance of both approaches on Firefox 118:

1. **Regex Matching (Test Name: "regex")**: 8781050 executions per second.
2. **String Splitting and Iteration (Test Name: "split and for each")**: 158288.609375 executions per second.

The benchmark highlights a significant performance difference between the two approaches, suggesting that regex matching might be faster in this scenario.

Related benchmarks:

str.match vs str.Split and for each (regex g flag) (version: 0)

Comparing performance of: regex vs split and for each

Created: 2 years ago by: Guest

Jump to the latest result

regex

split and for each

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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