Benchmark: Round Numbers to 2 digits

Script Preparation code:

var number = 12324242/432432432;
var result;

function round(value, decimals) {
  return Number(Math.round(value+'e'+decimals)+'e-'+decimals);
}

Tests:

toFixed
result = +(number.toFixed(2));
Math.round
result = Math.round((100 - (number) * 100) * 100) / 100;
Round function with correction
result = round(number, 2);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toFixed
Math.round
Round function with correction

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0

Browser/OS: Firefox 140 on Windows

View result in a separate tab

Test name	Executions per second
toFixed	9725693.0 Ops/sec
Math.round	547289088.0 Ops/sec
Round function with correction	4948126.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents a JavaScript microbenchmark that tests three different approaches for rounding numbers to two decimal places: `toFixed`, `Math.round`, and a custom implementation using a round function.

**Options Comparison**

1. **`toFixed()`**: This method uses the `toFixed()` function, which returns a string representing the number rounded to the specified number of decimals.
	* Pros:
		+ Simple to use
		+ Works with numbers and strings
	* Cons:
		+ May lead to precision issues due to rounding errors
2. **`Math.round()`**: This method uses the `round()` function, which returns the nearest integer or a number rounded to the specified decimal places.
	* Pros:
		+ Fast and efficient
		+ Works well for large numbers
	* Cons:
		+ May not produce the desired rounding behavior (e.g., negative values)
3. **Custom implementation using `round()`**: This method uses a custom function called `round()`, which multiplies and divides the number by 10 raised to the power of the decimal places, then takes the integer part.
	* Pros:
		+ Customizable precision
		+ Works well for both positive and negative numbers
	* Cons:
		+ May be slower than other methods due to unnecessary calculations

**Library: `round()`**

The custom implementation uses a `round()` function, which is not a standard JavaScript library. It appears to be a custom implementation of the rounding algorithm.

**Special JS Feature/Syntax: None**

There are no special JavaScript features or syntax used in this benchmark.

**Other Considerations**

When dealing with numerical precision and rounding issues, it's essential to consider factors like:

* The nature of the data (e.g., financial transactions vs. scientific calculations)
* The desired level of precision
* Potential edge cases (e.g., NaN, Infinity, or very large/small numbers)

**Alternatives**

For similar benchmarks, you can explore other approaches, such as:

* Using a dedicated library like [round.js](https://github.com/mike-lipson/round.js) for precise rounding.
* Implementing a custom rounding algorithm using bitwise operations (e.g., multiplying by 10^N and dividing by 10^N).
* Comparing different rounding modes, such as rounding to the nearest even digit or rounding to a specific decimal place.

Keep in mind that the best approach will depend on the specific requirements of your project.

Related benchmarks:

Round Numbers to 2 digits (version: 0)

Comparing performance of: toFixed vs Math.round vs Round function with correction

Created: 8 years ago by: Guest

Jump to the latest result

toFixed

Math.round

Round function with correction

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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