Benchmark: Regex whitespace check vs trim length

Script Preparation code:

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

Tests:

regex
!/\S/.test(str)
trim
!!str.trim().length

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: 4 months ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 143 on Android

View result in a separate tab

Test name	Executions per second
regex	31050934.0 Ops/sec
trim	37019048.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested on MeasureThat.net.

**What is being tested?**

The benchmark compares two approaches to check if a string contains whitespace:

1. **Regex**: Using a regular expression (`!/\S/.test(str)`) to check if the string has any non-whitespace characters.
2. **Trim length**: Checking the length of the trimmed string (`!!str.trim().length`) after removing all whitespace characters.

**Options compared**

The two options are compared in terms of performance, specifically:

* How many times can each option execute per second on a specific browser and device platform?
* Which approach is faster?

**Pros and Cons of each approach:**

1. **Regex ( !/\S/.test(str) )**
	* Pros:
		+ Simple to implement
		+ Can be used for more complex pattern matching
	* Cons:
		+ May be slower due to the overhead of regular expression execution
		+ Can be less efficient in terms of CPU cycles compared to trimming and checking length directly
2. **Trim length ( !!str.trim().length )**
	* Pros:
		+ Generally faster than regex due to fewer operations required
		+ More straightforward and efficient approach for simple whitespace checks
	* Cons:
		+ May require additional allocations for creating a new trimmed string object

**Library used**

None, but it's worth noting that the `trim()` method is part of the JavaScript String prototype.

**Special JS feature or syntax**

The question mark `!!` before `str.trim().length` is an example of optional chaining and the nullish coalescing operator (`??`). This syntax allows for more concise expressions and can improve performance by avoiding unnecessary operations. However, it's not a fundamental feature that would be considered essential to understand for general JavaScript programming.

**Other alternatives**

If you were to write this benchmark yourself, you might also consider comparing other approaches, such as:

* Using a dedicated whitespace removal library or function
* Checking the length of the string before and after trimming to ensure accuracy
* Comparing performance with different string types (e.g., text, buffer, etc.)
* Incorporating more test cases to cover edge cases and variations in browser behavior

Related benchmarks:

Regex whitespace check vs trim length (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):