Benchmark: Regex v split find str

Script Preparation code:

var str = 'Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxyAbcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy';

Tests:

Regex
(str.match(/A/g)||[]).length;
Split and Join
str.split("A").length - 1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex
Split and Join

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The benchmark consists of two test cases: "Regex" and "Split and Join". The script preparation code includes a long string with repeated substrings starting with "Abcd efghij klmnopqrstuv wxy".

**Test Cases**

1. **Regex**
	* Benchmark Definition: `(str.match(/A/g)||[]).length;`
	* Purpose: This test case measures the performance of the `match()` method with a regular expression that finds all occurrences of "A" in the string.
2. **Split and Join**
	* Benchmark Definition: `str.split("A").length - 1;`
	* Purpose: This test case measures the performance of splitting the string into substrings separated by the character "A".

**Comparison**

The two test cases are being compared to determine which approach is faster for processing the given string.

**Approaches**

There are three approaches being compared:

1. **Regex**: Using regular expressions to search for patterns in the string.
	* Pros:
		+ Can handle complex patterns and character classes.
		+ Can be efficient for large datasets if optimized properly.
	* Cons:
		+ Can be slower than other methods due to the overhead of compiling regular expressions.
		+ May have performance issues with very large or complex patterns.
2. **Split and Join**: Using string splitting and concatenation to separate substrings.
	* Pros:
		+ Can be faster for simple substring separation tasks.
		+ Less prone to performance issues due to the simplicity of the operation.
3. **Hybrid Approach**: Not explicitly tested, but implied by the benchmark structure.

**Library/Implementation Details**

The `match()` method is a built-in JavaScript function that uses regular expressions internally. The `split()` and `length` properties are also standard JavaScript properties.

No special JavaScript features or syntax are being used in these test cases.

**Other Alternatives**

If the benchmark was designed to compare other approaches, some alternatives might include:

1. **Using array methods**: Instead of splitting the string into substrings using `split()`, an alternative approach could be to use array methods like `map()` and `filter()` to achieve the same result.
2. **Regular expression optimization**: If optimizing regular expressions is important, other approaches might involve using techniques like lazy matching (`g` flag) or using a more efficient regex engine.

In summary, this benchmark compares the performance of two simple string processing operations: regular expression matching and substring separation using `split()` and concatenation. The results will help determine which approach is faster for these specific tasks.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36

Browser/OS: Chrome 106 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Regex	6531390.5 Ops/sec
Split and Join	11630442.0 Ops/sec

Related benchmarks:

Regex v split find str (version: 0)

Comparing performance of: Regex vs Split and Join

Created: 2 years ago by: Guest

Jump to the latest result

Regex

Split and Join

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):