Benchmark: Fastest way to detect an empty string - better test cases

Script Preparation code:

var strings = ['    ', '    a', 'a    ', '  a  '];

Tests:

regex
strings.filter(s=>/^\s+$/.test(s));
trim
strings.filter(s=>!s.trim())
trimStart
strings.filter(s=>s.trimStart())
trimEnd
strings.filter(s=>s.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: 6 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Windows

View result in a separate tab

Test name	Executions per second
regex	5549701.0 Ops/sec
trim	10098110.0 Ops/sec
trimStart	10933349.0 Ops/sec
trimEnd	11619358.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 6 days ago):

LLMs can make mistakes. Check important info.

The benchmark defined in the provided JSON tests various methods for detecting empty strings, particularly focusing on how these methods handle strings with leading or trailing whitespace. This scenario is highly relevant to developers working with user inputs, where it is essential to handle strings correctly.

### Benchmark Overview

**Objective:** To evaluate performance when filtering an array of strings to determine if they are empty after removing whitespace using various techniques.

**Tested Methods:**
1. **Regular Expression:**  
   `strings.filter(s => /^\\s+$/.test(s));`  
   This method uses a regular expression to check if the string consists solely of whitespace.

2. **Trim:**  
   `strings.filter(s => !s.trim());`  
   This checks if the string, when trimmed of whitespace from both ends, is empty.

3. **Trim Start:**  
   `strings.filter(s => s.trimStart());`  
   This uses the `trimStart()` method to remove whitespace from the beginning of the string only and checks if the result is truthy (non-empty).

4. **Trim End:**  
   `strings.filter(s => s.trimEnd());`  
   Similarly, this uses the `trimEnd()` method to remove whitespace from the end of the string and checks if the result is truthy.

### Results Analysis

The benchmark results provide the number of executions per second for each method using a specific browser, device platform, and operating system. Here are the results:

- **trimEnd:** 11,619,358 executions/sec
- **trimStart:** 10,933,349 executions/sec
- **trim:** 10,098,110 executions/sec
- **regex:** 5,549,701 executions/sec

### Pros and Cons of Each Method

1. **Regular Expression**
   - **Pros:** Can be very concise and powerful when matching complex patterns.
   - **Cons:** Regular expressions can be slower due to their processing overhead and complexity, especially with simple checks like whitespace.

2. **Trim Method**
   - **Pros:** Very straightforward; `trim()` is specifically designed for this purpose and operates optimally for removing leading and trailing whitespace.
   - **Cons:** Slightly more computationally expensive than `trimStart()` or `trimEnd()` if only one side is of interest, but still quite efficient in practice.

3. **Trim Start and Trim End**
   - **Pros:** These methods can be more efficient when only one side of the string needs to be cleaned, potentially resulting in faster execution than `trim()` when relevant.
   - **Cons:** They won't catch both leading and trailing whitespace at the same time, which might not be useful in some contexts where both sides need to be checked.

### Other Considerations

- **Context of Use:** In some scenarios, knowing if a string is empty or consists of only whitespace might be sufficient, while in other cases retaining some whitespace might be desired (e.g., formatting).
- **Compatibility:** While `trim()`, `trimStart()`, and `trimEnd()` are widely supported in modern browsers, using regular expressions can bring up concerns regarding readability and maintainability of the code.
  
### Alternatives

Aside from these methods, other approaches might include:
- **Looping through characters:** Manually iterate through each character in the string to check if all are whitespace (less efficient).
- **External Libraries:** Libraries like Lodash provide functions to check for empty or whitespace-only strings more robustly but may increase code complexity and overhead.
- **Custom Utility Functions:** Writing bespoke utility functions for detecting empty strings may optimize performance based on application-specific requirements.

Choosing the appropriate method not only depends on performance results but also on the specific needs and context of the application, such as code maintainability and readability.

Related benchmarks:

Fastest way to detect an empty string - better test cases (version: 1)

testing removing beginning and end whitespace vs trim

Comparing performance of: regex vs trim vs trimStart vs trimEnd

Created: 6 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 6 days ago):