Benchmark: toFixed vs toPrecision vs Math.round() vs Math.floorfast3

Script Preparation code:

var someFloat = 673.123456789;

Tests:

toFixed(4)
someFloat.toFixed(0);
toPrecision(0).toString()
someFloat.toPrecision(3);
(Math.round(*10000)/10000).toString()
Math.floor(someFloat);
Math.floor fast
~~someFloat

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toFixed(4)
toPrecision(0).toString()
(Math.round(*10000)/10000).toString()
Math.floor fast

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Safari/537.36

Browser/OS: Chrome 92 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
toFixed(4)	2601041.8 Ops/sec
toPrecision(0).toString()	3638400.5 Ops/sec
(Math.round(*10000)/10000).toString()	4799031.5 Ops/sec
Math.floor fast	14099165.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**What is being tested?**

MeasureThat.net is testing the performance of four different methods to round or approximate floating-point numbers in JavaScript:

1. `toFixed()`: Rounds a number to a specified number of decimal places.
2. `toPrecision()`: Rounds a number to a specified number of significant digits.
3. `Math.round()`: Rounds a number to the nearest integer.
4. A custom implementation, "Math.floor fast" (not an official JavaScript method), which likely uses a faster algorithm for rounding integers.

**Options compared**

The benchmark is comparing the performance of these four methods across different browsers and devices:

* Browser: Chrome 92
* Device Platform: Desktop (Mac OS X 10.15.7)
* Operating System: Mac OS X 10.15.7

**Pros and Cons**

Here's a brief summary of each method's pros and cons:

1. `toFixed(4)`: Pros - easy to use, straightforward implementation. Cons - may not be the most efficient way to round numbers, especially for large ranges.
2. `toPrecision(0).toString()`: Pros - similar to `toFixed()`, but allows for more control over precision. Cons - may require additional string conversion, which can impact performance.
3. `Math.round(*10000)/10000`.toString()`: Pros - uses a simple multiplication and division trick to round numbers quickly. Cons - may not be as intuitive or readable as other methods.
4. "Math.floor fast" (not an official JavaScript method): Pros - likely optimized for performance, especially for integer rounding. Cons - may not be widely supported or understood by developers.

**Library usage**

None of the benchmark cases explicitly use any external libraries.

**Special JS features or syntax**

The custom implementation, "Math.floor fast", is a notable exception. While it's not an official JavaScript method, it uses a clever trick to quickly round integers without using `Math.round()`.

**Other alternatives**

For rounding numbers in JavaScript, other methods could be considered:

* Using `Number.EPSILON` for a relative epsilon-based rounding approach
* Implementing a custom rounding algorithm that takes into account the magnitude and sign of the number
* Using a library like `mathjs` or ` numeral.js` for more advanced mathematical operations

Keep in mind that these alternatives may have their own performance trade-offs and are not as widely supported as the four methods tested in this benchmark.

Related benchmarks:

toFixed vs toPrecision vs Math.round() vs Math.floorfast3 (version: 0)

Comparing performance of: toFixed(4) vs toPrecision(0).toString() vs (Math.round(*10000)/10000).toString() vs Math.floor fast

Created: 3 years ago by: Guest

Jump to the latest result

toFixed(4)

toPrecision(0).toString()

(Math.round(*10000)/10000).toString()

Math.floor fast

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):