Benchmark: toFixed vs toPrecision vs bitwise

Script Preparation code:

var someFloat = 0.123456789;

Tests:

toFixed(4)
someFloat.toFixed(4)
toPrecision(4).toString()
someFloat.toPrecision(4)
(Math.round(*10000)/10000).toString()
(someFloat*10000|0)/10000

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36

Browser/OS: Chrome 106 on Windows

View result in a separate tab

Test name	Executions per second
toFixed(4)	3784979.0 Ops/sec
toPrecision(4).toString()	4191842.8 Ops/sec
(Math.round(*10000)/10000).toString()	10103409.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**What is tested on the provided JSON?**

The benchmark tests three different approaches to round or format a floating-point number:

1. `toFixed(4)`: This method returns a string representation of the float, rounded to 4 decimal places.
2. `toPrecision(4).toString()`: This method returns a string representation of the float, with a precision of 4 decimal places. The `toPrecision()` method is a non-standard property that was introduced in older versions of JavaScript engines.
3. `(someFloat*10000|0)/10000` (also known as bitwise rounding): This method uses a bitwise operation to round the float to 4 decimal places.

**Options compared**

The benchmark compares these three approaches, allowing users to see which one is faster and more efficient in terms of CPU cycles.

**Pros and Cons of each approach**

1. `toFixed(4)`:
	* Pros: Easy to read and understand, widely supported by modern browsers.
	* Cons: Can result in a string that contains more decimal places than needed if the float has no fractional part.
2. `toPrecision(4).toString()`: (Note: This property was introduced in older JavaScript versions and is not widely supported.)
	* Pros: Can provide more control over the precision of the formatted number.
	* Cons: Not widely supported, can be slower due to the non-standard nature of this property.
3. `(someFloat*10000|0)/10000` (bitwise rounding):
	* Pros: Fast and efficient, uses bitwise operations which are often faster than arithmetic operations.
	* Cons: Can be less readable and harder to understand for developers who are not familiar with bitwise rounding.

**Other considerations**

The benchmark also considers the device platform, operating system, and browser version, which can affect the performance of each approach. It's essential to note that the results might vary depending on these factors.

**Libraries used**

None of the provided benchmarks use external libraries. The script preparation code includes a simple variable `someFloat` with a value of `0.123456789`, and no library functions are called in any of the test cases.

**Special JavaScript features or syntax**

The only special feature mentioned is bitwise rounding, which uses the bitwise OR operator (`|`) to perform a round-to-nearest-even operation on the float. This technique is used in some programming languages, but it's not a standard JavaScript feature.

**Alternatives**

If users want to explore alternative approaches to rounding floats, they can try:

* Using `Number.EPSILON` and arithmetic operations to implement their own rounding algorithm.
* Investigating other libraries or frameworks that provide optimized floating-point arithmetic functions.
* Exploring different bitwise operators and techniques for rounding floats.

Keep in mind that the best approach will depend on specific use cases and performance requirements.

Related benchmarks:

toFixed vs toPrecision vs bitwise (version: 0)

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

Created: 2 years ago by: Guest

Jump to the latest result

toFixed(4)

toPrecision(4).toString()

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