Benchmark: Regex vs Split for base64 string

Script Preparation code:

var string = `eyJ0ZXN0IjoxLCJjb21wYW5pZXMiOlsxLDIsMyw0LDUsNl0sInVzZXIiOiJ0ZXN0IiwiZGF0ZSI6Illlc3RlcmRheSIsInN0YXJ0QXQiOiIyMDIzLTExLTAxVDAwOjAwOjAwLjAwMFoifQ==`;

Tests:

Regex
string.replace(/(=+)$/, '')
Split
string.split('=')[0]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex
Split

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**What is being tested?**

The provided benchmark compares two approaches to manipulate a base64 string: using regular expressions (regex) and splitting the string using the `=` character as a delimiter.

In this specific test case, the base64 string is:
```
eyJ0ZXN0IjoxLCJjb21wYW5pZXMiOlsxLDIsMyw0LDUsNl0sInVzZXIiOiJ0ZXN0IiwiZGF0ZSI6Illlc3RlcmRheSIsInN0YXJ0QXQiOiIyMDIzLTExLTAxVDAwOjAwOjAwLjAwMFoifQ==
```
The test case consists of two individual tests:

1. "Regex": This test uses the `replace()` method with a regex pattern to remove the last character (`=`) from the base64 string.
2. "Split": This test splits the base64 string using the `=` character as a delimiter and takes the first part.

**Options compared**

The two approaches are compared in terms of their performance, specifically:

* Time taken to execute each approach
* Number of executions per second

**Pros and Cons of each approach:**

1. **Regex ("Regex")**:
	* Pros:
		+ Can be more flexible for complex string manipulation
		+ Does not require splitting the string into parts
	* Cons:
		+ May be slower due to regex parsing and compilation overhead
		+ Can be more memory-intensive if dealing with large strings
2. **Split ("Split")**:
	* Pros:
		+ Typically faster due to simpler string manipulation
		+ Less memory-intensive compared to regex
	* Cons:
		+ May not be suitable for complex string manipulation or edge cases

**Library/Dependency**

None explicitly mentioned, but `String.prototype.replace()` and `String.prototype.split()` are built-in methods in JavaScript.

**Special JS feature/syntax**

None mentioned, but this benchmark focuses on basic string manipulation using native JavaScript methods.

**Other alternatives**

If you were to modify the test case or use a different approach, some alternatives could be:

* Using other regex flavors (e.g., `RegExp`)
* Implementing custom string splitting logic
* Utilizing specialized libraries for string manipulation (e.g., `lodash.string`)

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.1.1 Safari/605.1.15

Browser/OS: Safari 17 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Regex	5931178.0 Ops/sec
Split	15659519.0 Ops/sec

Related benchmarks:

Regex vs Split for base64 string (version: 0)

Comparing performance of: Regex vs Split

Created: one year ago by: Guest

Jump to the latest result

Regex

Split

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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