Benchmark: Trim leading and trailing slash (regex vs split filter)

Script Preparation code:

var s = '//the//////quick/brown///////////fox/jumps/over//the/lazy/dog////';

Tests:

simple regex
s.replace(/\/{2,}/g, "/").replace(/(^\/+|\/+$)/g, "");
regex with no lookbehind
s.replace(/\/{2,}/g, "/").replace(/(^\/+|(?<!\/)\/+$)/g, "");
split + filter + join
s.split("/").filter(Boolean).join("/");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
simple regex
regex with no lookbehind
split + filter + join

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36

Browser/OS: Chrome 138 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
simple regex	3845017.8 Ops/sec
regex with no lookbehind	3780821.5 Ops/sec
split + filter + join	4509587.0 Ops/sec

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 and explain what's being tested, along with the pros and cons of each approach.

**Benchmark Definition**

The benchmark is comparing three different methods to trim leading and trailing slashes from a string:

1. Using a regular expression (`regex` approach)
2. Splitting the string using `/` as a delimiter and filtering out empty strings (`split + filter` approach)
3. Joining the split string using `/` as a delimiter (no filtering)

**Options Compared**

The three approaches are compared in terms of execution speed.

**Pros and Cons of Each Approach:**

1. **Regex Approach**
	* Pros:
		+ Can handle complex cases with nested slashes
		+ Often faster than other methods for simple trimming operations
	* Cons:
		+ Can be slower due to the overhead of regular expression compilation and execution
		+ May not work as expected if the input string contains invalid characters or unexpected whitespace
2. **Split + Filter + Join Approach**
	* Pros:
		+ Simple to understand and implement
		+ Can handle edge cases with empty strings (filtered out)
	* Cons:
		+ May be slower than regex due to the overhead of creating and manipulating arrays
		+ Requires an extra step to join the filtered array back into a string
3. **No Filter Approach**
	* Pros:
		+ Fastest approach, as it eliminates the need for filtering or joining operations
	* Cons:
		+ Ignores leading and trailing slashes (unless they're exactly 1 slash)
		+ May not work well with edge cases like empty strings or multiple consecutive slashes

**Library Used**

The benchmark definition uses no external libraries. However, it assumes that the input string `s` is a valid JavaScript string.

**Special JS Feature/Syntax**

This benchmark does not use any special JavaScript features or syntax beyond standard ECMAScript functions and operators (e.g., `replace`, `split`, `join`, `filter`). If you're familiar with more advanced features like async/await, let's see how the results would differ!

**Alternative Approaches**

Other approaches to trimming leading and trailing slashes might include:

* Using a dedicated string manipulation library or utility function
* Implementing a custom algorithm that optimizes for performance or edge cases
* Utilizing browser-specific features or APIs (e.g., WebAssembly, SIMD instructions)

Keep in mind that these alternatives may not be directly comparable to the provided benchmark definition. The focus of this explanation is on understanding the original approach and its pros and cons.

Related benchmarks:

Trim leading and trailing slash (regex vs split filter) (version: 0)

Comparing performance of: simple regex vs regex with no lookbehind vs split + filter + join

Created: 2 years ago by: Guest

Jump to the latest result

simple regex

regex with no lookbehind

split + filter + join

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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