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

~~(someFloat * 10000) / 10000

12.8M/s

toPrecision(4).toString()

4.6M/s

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

4.3M/s

toFixed(4)

3.6M/s

View exact numbers

Test name	Executions per second
✓ ~~(someFloat * 10000) / 10000	12,792,228 Ops/sec
toPrecision(4).toString()	4,563,444 Ops/sec
(Math.round(*10000)/10000).toString()	4,327,884 Ops/sec
toFixed(4)	3,565,014 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.

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

Go 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

Go 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):

Related benchmarks

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