Benchmark: toFixed vs toPrecision vs Math.round() vs ~~(someFloat * 10000) / 10000

Script Preparation code:

var someFloat = 0.123456789;

Tests:

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

Browser/OS: Chrome 124 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
toFixed(4)	3565014.0 Ops/sec
toPrecision(4).toString()	4563444.0 Ops/sec
(Math.round(*10000)/10000).toString()	4327884.5 Ops/sec
~~(someFloat * 10000) / 10000	12792228.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is tested, compared, pros and cons of each approach, and other considerations.

**Benchmark Definition**

The benchmark definition represents a single test case for a JavaScript function. In this case, there are four different approaches to achieve a specific result:

1. `toFixed(4)`: Formats a floating-point number as a fixed-point number with 4 decimal places.
2. `toPrecision(4).toString()`: Converts a floating-point number to a string using the `toPrecision()` method, which allows specifying the precision (in this case, 4), and then calls `toString()` on the result.
3. `(Math.round(*10000)/10000).toString()`: Multiplies the input value by 10,000, rounds it to the nearest integer using `Math.round()`, and then divides by 10,000 to get a float between 0 and 1. Finally, calls `toString()` on the result.
4. `~~(someFloat * 10000) / 10000`: Uses the bitwise NOT operator (`~`) to perform integer arithmetic on the input value multiplied by 10,000.

**Comparison**

These approaches are compared in terms of their performance and accuracy when used with a specific test case: `var someFloat = 0.123456789;`. The goal is to determine which approach is the fastest or most accurate for this particular use case.

**Pros and Cons**

1. **`toFixed(4)`**:
	* Pros: Simple, widely supported, and easy to read.
	* Cons: May not be suitable for all decimal places or rounding styles (e.g., scientific notation).
2. **`toPrecision(4).toString()`**:
	* Pros: More flexible than `toFixed()`, allowing for custom precision and formatting.
	* Cons: May require additional overhead due to the method call and string conversion.
3. **`(Math.round(*10000)/10000).toString()`**:
	* Pros: Can be more accurate than simple arithmetic operations, as it takes into account rounding errors.
	* Cons: More complex and potentially slower than other approaches.
4. **`~~(someFloat * 10000) / 10000```**:
	* Pros: Simple and lightweight, using bitwise operations to achieve the desired result.
	* Cons: May not be as accurate or flexible as other approaches, as it relies on integer arithmetic.

**Other Considerations**

* The use of `toPrecision()` is an interesting choice, as it allows for more control over the formatting process. However, it may introduce additional overhead due to method calls and string conversions.
* The approach using `Math.round()` with multiplication and division by large factors is less common and might be optimized away by the browser's Just-In-Time (JIT) compiler or other performance optimizations.

**Alternatives**

Other alternatives for achieving similar results could include:

* Using a dedicated rounding library, such as `round.js`
* Employing advanced arithmetic techniques, like arbitrary-precision arithmetic
* Leveraging specialized libraries or frameworks for numerical computations

Keep in mind that the specific choice of approach depends on the requirements and constraints of your use case.

Related benchmarks:

toFixed vs toPrecision vs Math.round() vs ~~(someFloat * 10000) / 10000 (version: 0)

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

Created: one year ago by: Guest

Jump to the latest result

toFixed(4)

toPrecision(4).toString()

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

~~(someFloat * 10000) / 10000

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

toFixed vs toPrecision vs Math.round() vs ~~(someFloat * 10000) / 10000 (version: 0)

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

Created: one year ago by: Guest

Jump to the latest result

toFixed(4)

toPrecision(4).toString()

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

~~(someFloat * 10000) / 10000

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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