Benchmark: toFixed vs toPrecision vs Math.round() as float

Script Preparation code:

var someFloat = 0.123456789;

Tests:

parseFloat(toFixed(4))
parseFloat(someFloat.toFixed(4));
toPrecision(4)
someFloat.toPrecision(4)
Math.round(*10000)/10000
Math.round(someFloat*10000)/10000

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
parseFloat(toFixed(4))
toPrecision(4)
Math.round(*10000)/10000

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/112.0.0.0 Safari/537.36

Browser/OS: Chrome 112 on Windows

View result in a separate tab

Test name	Executions per second
parseFloat(toFixed(4))	527685.9 Ops/sec
toPrecision(4)	787776.7 Ops/sec
Math.round(*10000)/10000	1033648.8 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 Purpose**

The benchmark is designed to compare three different approaches for converting a floating-point number to a string representation with a specified number of decimal places:

1. `toFixed()`
2. `toPrecision()`
3. `Math.round()` followed by division by 10,000 and then rounding again

**Options Compared**

* `toFixed(4)`: This method returns a string representation of the float with exactly 4 decimal places.
* `toPrecision(4)`: This method returns a string representation of the float with at most 4 significant digits.
* `Math.round(*10000)/10000`: This approach first multiplies the float by 10,000, rounds it using `Math.round()`, and then divides the result by 10,000.

**Pros and Cons**

* **toFixed(4)**:
	+ Pros: Easy to understand and use, produces a fixed-precision output.
	+ Cons: May not be suitable for large numbers or numbers with many decimal places.
* **toPrecision(4)**:
	+ Pros: More flexible than `toFixed()`, can handle large numbers and numbers with many decimal places.
	+ Cons: Can result in trailing zeros, which may not be desirable.
* **Math.round(*10000)/10000**:
	+ Pros: Can produce more accurate results for certain types of numbers (e.g., large integers).
	+ Cons: May not be suitable for all use cases, as it involves extra operations and potential rounding errors.

**Library and Special JS Features**

The benchmark uses the `parseFloat()` function, which is a built-in JavaScript function. No external libraries are required.

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

**Other Alternatives**

If you need to convert floating-point numbers to string representations with a specified number of decimal places, consider using other approaches, such as:

* Using the `Number()` function with the desired precision: `Number(someFloat).toPrecision(4)`
* Using the `BigInt()` function (for large integers): `BigInt(someFloat).toString(2)` (note that this will not produce a standard decimal representation)
* Implementing your own custom solution using arithmetic and string manipulation.

Keep in mind that each approach has its pros and cons, and the best choice depends on your specific use case.

Related benchmarks:

toFixed vs toPrecision vs Math.round() as float (version: 0)

Comparing performance of: parseFloat(toFixed(4)) vs toPrecision(4) vs Math.round(*10000)/10000

Created: one year ago by: Guest

Jump to the latest result

parseFloat(toFixed(4))

toPrecision(4)

Math.round(*10000)/10000

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):