Benchmark: regex removing whitespace vs trim vs trimStart vs trimEnd

Script Preparation code:

var string = '    fsajdf asdfjosa fjoiawejf oawjfoei jaosdjfsdjfo sfjos 2324234 sdf safjao j o        sdlfks dflks l      '

Tests:

regex
string.replace(/\s+$/g, '')
trim
string.trim()
trimStart
string.trimStart()
trimEnd
string.trimEnd()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex
trim
trimStart
trimEnd

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 27 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
regex	2378059.5 Ops/sec
trim	60003216.0 Ops/sec
trimStart	85229608.0 Ops/sec
trimEnd	77633024.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 27 days ago):

LLMs can make mistakes. Check important info.

The benchmark focuses on evaluating the performance of different methods for removing whitespace from a string in JavaScript. Specifically, it compares four approaches:

1. **Regex Replacement (`string.replace(/\\s+$/g, '')`)**:
   - **Description**: This uses a regular expression to replace all whitespace characters at the end of a string with an empty string. 
   - **Pros**: Regex can be very powerful and flexible, allowing for complex pattern matching and manipulation.
   - **Cons**: Regex operations can be slower than simpler string methods, especially when the regex is complex. The overhead of regex parsing might make it less performant for simpler use cases like trimming whitespaces.

2. **Trim (`string.trim()`)**:
   - **Description**: This method removes whitespace from both the beginning and end of a string.
   - **Pros**: `trim()` is straightforward and optimized for this specific task of trimming, making it very efficient. It's well-understood and widely used for general whitespace removal.
   - **Cons**: It does not allow for selective trimming of only the start or end of the string.

3. **Trim Start (`string.trimStart()`)**:
   - **Description**: This method only removes whitespace from the beginning of the string.
   - **Pros**: Efficient for cases where only leading whitespace needs to be addressed. It’s optimized specifically for this purpose.
   - **Cons**: If end whitespace also needs to be removed, this method won't fulfill that requirement.

4. **Trim End (`string.trimEnd()`)**:
   - **Description**: This method only removes whitespace from the end of the string.
   - **Pros**: Like `trimStart()`, this is optimized for its specific task, providing good performance when dealing with trailing whitespace.
   - **Cons**: Similar to `trimStart()`, if leading whitespace also requires removal, this method is insufficient by itself.

### Performance Results

The benchmark results show the `ExecutionsPerSecond` metric for each method tested:

- **trimStart**: 85,229,608 ops/sec - This was the fastest method in the tests.
- **trimEnd**: 77,633,024 ops/sec - Also performed well, but not as fast as `trimStart`.
- **trim**: 60,003,216 ops/sec - Marginally slower than both `trimStart` and `trimEnd`.
- **regex**: 2,378,059.5 ops/sec - The regex method was significantly slower compared to the built-in trim methods.

### Considerations

- **Simplicity and Use Case**: If your use case only requires removing whitespace from one side of the string, using `trimStart` or `trimEnd` is advisable for better performance. For general trimming, `trim()` is the best choice, while the regex method should be avoided for simple cases.
  
- **Readability**: Built-in methods like `trim()`, `trimStart()`, and `trimEnd()` are more readable and self-explanatory than regex. This is crucial for code maintainability and team collaboration.

- **Browser Support**: The methods `trim()`, `trimStart()`, and `trimEnd()` are widely supported across modern browsers, while regex is a fundamental feature of JavaScript.

### Alternatives

- **Manual Whitespace Removal**: You could manually trim whitespace by manipulating string indices, but this would be more cumbersome and error-prone compared to using native methods.
- **Libraries**: For more complex string manipulation scenarios where persistent modification is needed, libraries such as Lodash might be useful. Lodash offers variety of utility functions, including those for string manipulation, but in many cases, the native methods provide adequate performance and simplicity.

In conclusion, the benchmark illustrates that for standard whitespace removal tasks, JavaScript's native string methods (`trim`, `trimStart`, and `trimEnd`) significantly outperform regex alternatives. Software engineers should prefer these built-in solutions for optimal performance and code clarity.

Related benchmarks:

regex removing whitespace vs trim vs trimStart vs trimEnd (version: 1)

testing removing end whitespace vs trimEnd

Comparing performance of: regex vs trim vs trimStart vs trimEnd

Created: 27 days ago by: Guest

Jump to the latest result

regex

trim

trimStart

trimEnd

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 27 days ago):