Benchmark: Fastest way to detect an empty string

Script Preparation code:

var string = '    '

Tests:

regex
string.replace(/^\s/g, '') === 0
trim
string.trim() === 0
trimStart
string.trimStart() === 0
trimEnd
string.trimEnd() === 0

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

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, compared options, pros/cons of each approach, library usage, special JavaScript features or syntax, and other alternatives.

**Benchmark Overview**

The benchmark measures which method (regex, trim, trimStart, or trimEnd) is the fastest for detecting an empty string in a given input string. The input string is initially set to a single whitespace character using the "Script Preparation Code".

**Test Cases**

There are four test cases:

1. **Regex**: Tests if `string.replace(/^\\s/g, '') === 0` is faster.
2. **Trim**: Tests if `string.trim() === 0` is faster.
3. **TrimStart**: Tests if `string.trimStart() === 0` is faster.
4. **TrimEnd**: Tests if `string.trimEnd() === 0` is faster.

**Comparison of Methods**

* **Regex**: This method uses a regular expression to remove leading whitespace characters from the input string. While it's efficient, regex can be slower than other methods for simple string trimming tasks due to its overhead and parsing requirements.
* **Trim**: This method uses the `trim()` method, which removes leading and trailing whitespace characters from the input string. It's a popular choice for basic string trimming, but might not be as fast as other methods in certain cases.
* **TrimStart** and **TrimEnd**: These methods are similar to trim() but only remove leading or trailing whitespace characters, respectively.

**Pros and Cons of Each Approach**

* **Regex**:
	+ Pros: Effective for removing leading whitespace characters, can handle edge cases like multiple consecutive whitespace characters.
	+ Cons: Can be slower than other methods due to its overhead and parsing requirements.
* **Trim**:
	+ Pros: Fast and efficient for basic string trimming tasks.
	+ Cons: May not remove all trailing whitespace characters if the input string ends with a non-whitespace character.
* **TrimStart** and **TrimEnd**:
	+ Pros: Faster than trim() in some cases, as they only need to remove one type of whitespace character.
	+ Cons: May be slower than regex for complex trimming tasks.

**Library Usage**

There is no explicit library usage mentioned in the benchmark, but it's worth noting that the `trim()` method uses a proprietary implementation under the hood (specifically, it uses a simple algorithm involving ASCII values).

**Special JavaScript Features or Syntax**

None are explicitly mentioned in this benchmark. However, if we consider the regex pattern `/^\\s/g`, we can break it down:

* `/`: Starts the regular expression.
* `\s`: Matches any whitespace character (including spaces, tabs, and line breaks).
* `^`: Matches the start of the string.
* `g` : Global flag, which allows the regex to match all occurrences in the string.

**Other Alternatives**

If you're looking for alternative methods or optimizations for detecting an empty string, some possible approaches include:

1. Using a simple string comparison (e.g., `string === ''`).
2. Using a more advanced algorithm like Boyer-Moore or KMP.
3. Using a library like `lodash` or `underscore` which provides optimized implementation of various string manipulation methods.

However, it's essential to note that the benchmark already tests four common approaches (regex, trim, trimStart, and trimEnd), so exploring other alternatives might not provide significant performance improvements for this specific use case.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:82.0) Gecko/20100101 Firefox/82.0

Browser/OS: Firefox 82 on Windows

View result in a separate tab

Test name	Executions per second
regex	17392460.0 Ops/sec
trim	37788244.0 Ops/sec
trimStart	30742754.0 Ops/sec
trimEnd	29807112.0 Ops/sec

Related benchmarks:

Fastest way to detect an empty string (version: 0)

testing removing beginning and end whitespace vs trim

Comparing performance of: regex vs trim vs trimStart vs trimEnd

Created: 4 years ago by: Registered User

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 llama3.2:3b, generated 26 days ago):