Benchmark: JS Math.round vs toPrecision + toString

Script Preparation code:

var someFloat = 0.123456789;

Tests:

Math.round
Math.round(someFloat);
toPrecision + toString
someFloat.toPrecision(4).toString();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Math.round
toPrecision + toString

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/108.0.0.0 Safari/537.36

Browser/OS: Chrome 108 on Windows

View result in a separate tab

Test name	Executions per second
Math.round	9317483.0 Ops/sec
toPrecision + toString	9779582.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is designed to compare two approaches for rounding a floating-point number: `Math.round()` and using `toPrecision` followed by `toString`. The script preparation code initializes a variable `someFloat` with a decimal value of 0.123456789, which will be used as the input for both tests.

**Options Compared**

Two options are being compared:

1. **Math.round()**: This is a built-in JavaScript function that rounds a number to the nearest integer.
2. **toPrecision + toString**: This approach involves using `toPrecision` with a precision of 4 to convert the floating-point number to a string, and then converting that string back to a number using `toString`. The resulting number will be rounded to the nearest integer.

**Pros and Cons**

**Math.round()**

Pros:

* Simple and straightforward implementation.
* Fast and efficient, as it uses a lookup table to determine the rounding behavior.
* Widely supported across browsers and platforms.

Cons:

* May not provide accurate results for very large or very small numbers due to the use of integer arithmetic.
* Can lead to precision errors if not used carefully.

**toPrecision + toString**

Pros:

* Provides more control over the rounding behavior, as the precision can be adjusted.
* Can help avoid precision errors by converting the number to a string before rounding.

Cons:

* More complex and computationally expensive than `Math.round()`, especially for large numbers.
* May not be as fast or efficient as `Math.round()` due to the conversion to a string.

**Library Usage**

There is no explicit library usage in this benchmark, but it's worth noting that some browsers may have additional libraries or extensions that could affect the performance of these tests.

**Special JavaScript Features or Syntax**

None are explicitly mentioned in the provided code, but it's possible that there might be other factors at play (e.g., browser-specific optimizations or caching) that could impact the results.

**Other Alternatives**

If you want to explore alternative approaches for rounding numbers, here are a few options:

1. **Big.js**: A library for precise floating-point arithmetic.
2. **Decimal.js**: Another library for precise decimal calculations.
3. **Fixed.js**: A library for fixed-point arithmetic (integer-based).

These libraries can provide more accurate results and better control over the rounding behavior, but may also introduce additional complexity and computational overhead.

Keep in mind that this benchmark is focused on comparing two specific approaches within JavaScript, so exploring alternative libraries or syntax might not be directly relevant to the current comparison.

Related benchmarks:

JS Math.round vs toPrecision + toString (version: 0)

Comparing performance of: Math.round vs toPrecision + toString

Created: one year ago by: Guest

Jump to the latest result

Math.round

toPrecision + toString

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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