Benchmark: Detecting an Empty or Whitespace String using RegEx vs trim

Script Preparation code:

var testString = "    ";

Tests:

RegEx
testString.match(/^ *$/) ? true : false
Trim
testString.trim().length === 0

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegEx
Trim

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:123.0) Gecko/20100101 Firefox/123.0

Browser/OS: Firefox 123 on Windows

View result in a separate tab

Test name	Executions per second
RegEx	30112262.0 Ops/sec
Trim	2391814144.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the explanation into smaller parts to make it easier to understand.

**Benchmark Definition**

The benchmark measures the performance of two approaches to detecting an empty or whitespace string: using Regular Expressions (RegEx) and trimming the string. The test strings are set to contain only whitespace characters (`"    "`).

**Options Compared**

Two options are being compared:

1. **RegEx**: This approach uses a regular expression to match any whitespace characters at the beginning of the string (`^ *`). If the pattern matches, it returns `true`, otherwise `false`.
2. **Trim**: This approach uses the built-in `trim()` method to remove leading and trailing whitespace characters from the string.

**Pros and Cons**

**RegEx:**

Pros:

* Can be used for more complex string matching tasks.
* Can be flexible in its pattern (e.g., match any whitespace character, including newline).

Cons:

* Can be slower than trimming due to the overhead of parsing the regular expression.
* May require more memory allocation, as the engine needs to create a regular expression object.

**Trim:**

Pros:

* Generally faster and more efficient, as it uses an optimized algorithm for string trimming.
* Requires less memory allocation, as it only creates a temporary string object.

Cons:

* Limited flexibility in terms of pattern matching.
* May not work correctly with strings containing non-ASCII characters or special characters.

**Library Used**

The `match()` method is used to execute the RegEx pattern. The purpose of this method is to search for a match in the string and return the result.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax used in this benchmark that would require prior knowledge. However, understanding regular expressions can be helpful.

**Other Alternatives**

If you need to detect empty or whitespace strings, other alternatives could include:

* Using a more specific RegEx pattern (e.g., `^\\s+$` for matching only whitespace characters at the start and end of the string).
* Using other string manipulation methods, such as `replace()` or `slice()`, to remove leading/trailing whitespace.
* Implementing your own trimming algorithm using bitwise operations.

Keep in mind that these alternatives might have different performance characteristics and requirements for specific use cases.

Related benchmarks:

Detecting an Empty or Whitespace String using RegEx vs trim (version: 0)

Comparing performance of: RegEx vs Trim

Created: 2 years ago by: Guest

Jump to the latest result

RegEx

Trim

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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