Benchmark: Float string optimization: parseFloat() vs regex, full version

Tests:

parseFloat()
var string = parseFloat((3/2).toFixed(4)).toString();
regex
var string = (3/2).toFixed(4).replace('^[+-]?([0-9]*[.])?[0-9]+$', '');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
parseFloat()
regex

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Windows

View result in a separate tab

Test name	Executions per second
parseFloat()	1703416.9 Ops/sec
regex	3463378.8 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

LLMs can make mistakes. Check important info.

This benchmark tests two different ways to convert a floating-point number (3/2) into a string with four decimal places: using `parseFloat()` and using a regular expression.

**Options Compared:**

* **`parseFloat()`:** This built-in JavaScript function directly parses a string and returns the corresponding numerical value. In this case, it's used to parse the result of `(3/2).toFixed(4)`, which is already a string with four decimal places.
* **Regular Expression:** This approach uses a regular expression (`^[+-]?([0-9]*[.])?[0-9]+$`) to remove any unnecessary characters from the string representation of `(3/2).toFixed(4)`.

**Pros and Cons:**

* **`parseFloat()`:**  
    * **Pros:** Simpler, more concise code. 
    * **Cons:** Might be less flexible if you need to perform more complex string manipulations before parsing.
* **Regular Expression:** 
    * **Pros:** More control over the final string format. Can handle edge cases and different input formats.
    * **Cons:** More complex code to write and understand, potentially slower execution due to the regex matching process.

**Other Considerations:**

* **Performance:** The benchmark results show that `parseFloat()` is significantly faster than using a regular expression in this specific case.  This highlights the importance of benchmarking for performance optimization.
* **Readability:** While both approaches work, `parseFloat()` is generally considered more readable and easier to understand.

**Alternatives:**

* **String Manipulation Functions:** You could use built-in JavaScript string methods like `substring`, `slice`, or `replace` to achieve a similar result as the regular expression. This might be a good compromise between performance and readability.
* **Third-party Libraries:** There are libraries specifically designed for number formatting, which might offer more features and flexibility.

Let me know if you have any other questions!

Related benchmarks:

Float string optimization: parseFloat() vs regex, full version (version: 0)

To get a cleaned-up float number with a limited number of digits of precision, which is faster: parsefloat() or a regular expression?

Comparing performance of: parseFloat() vs regex

Created: 5 years ago by: Guest

Jump to the latest result

parseFloat()

regex

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):