Benchmark: js math vs toLocaleString

Tests:

Rounding
const number = 1234.567 % 60 const c = Math.round(number * 10) / 10
localString
const number = 1234.567 % 60 const c = number.toLocaleString(undefined, { maximumFractionDigits: 1, minimumFractionDigits: 0 })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Rounding
localString

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's being tested.

**Benchmark Overview**

MeasureThat.net provides a platform for users to create and run JavaScript microbenchmarks. The benchmark in question compares two approaches: manual rounding using `Math.round()` and utilizing the `toLocaleString()` method with precision options.

**Test Cases**

There are two individual test cases:

1. **Rounding**: This test case measures the performance of manually rounding a decimal number using `Math.round()`. The benchmark definition is:
```javascript
const number = 1234.567 % 60
const c = Math.round(number * 10) / 10
```
2. **localString**: This test case measures the performance of using the `toLocaleString()` method with precision options to round a decimal number. The benchmark definition is:
```javascript
const number = 1234.567 % 60
const c = number.toLocaleString(undefined, { maximumFractionDigits: 1, minimumFractionDigits: 0 })
```
**Comparison Options**

The two approaches being compared are:

* **Manual Rounding**: Using `Math.round()` to round the decimal number.
	+ Pros:
		- Simple and widely supported.
		- Easy to implement.
	+ Cons:
		- May lead to rounding errors, especially for large numbers or precise values.
		- Can be slower due to the need for manual calculation.
* **toLocaleString() with Precision Options**: Using the `toLocaleString()` method with precision options to round the decimal number.
	+ Pros:
		- Provides more accurate results compared to manual rounding.
		- Often faster and more efficient, as it leverages the browser's built-in rounding capabilities.

**Library:**

* **Locale API**: The `toLocaleString()` method is part of the Locale API in JavaScript. This library provides a standardized way for applications to handle localized formatting of numbers, dates, and other numeric values.

**Special JS Feature/Syntax:**

None mentioned. Both test cases use standard JavaScript syntax.

**Other Considerations**

When choosing between manual rounding and using `toLocaleString()` with precision options, consider the trade-offs:

* Accuracy: If precision is crucial, using `toLocaleString()` might be a better choice.
* Performance: Manual rounding can lead to slower performance due to the need for manual calculation. However, this difference may not be significant in most cases.

**Alternatives**

Other approaches you could explore when comparing rounding methods include:

* Using a dedicated library like the `decimal.js` library, which provides precise decimal arithmetic and rounding capabilities.
* Implementing a custom rounding function using a more efficient algorithm, such as the "banker's rounding" method.
* Considering alternative formatting options, like scientific notation or fixed-point notation.

In summary, MeasureThat.net's benchmark compares two approaches to rounding decimal numbers: manual rounding using `Math.round()` and utilizing the `toLocaleString()` method with precision options. The latter approach provides more accurate results but may have slightly different performance characteristics compared to the former.

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Browser/OS: Chrome 125 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Rounding	15854440.0 Ops/sec
localString	96605.9 Ops/sec

Related benchmarks:

js math vs toLocaleString (version: 0)

Comparing performance of: Rounding vs localString

Created: 2 years ago by: Guest

Jump to the latest result

Rounding

localString

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):