Benchmark: toFixed vs toPrecision vs Math.round() 2

Script Preparation code:

var someFloat = 0.123456789;

Tests:

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

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/113.0.0.0 Safari/537.36

Browser/OS: Chrome 113 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
toFixed(4)	9817537.0 Ops/sec
toPrecision(4).toString()	10905133.0 Ops/sec
(Math.round(*10000)/10000).toString()	11736922.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark that compares the performance of three different methods to round or format floating-point numbers: `toFixed()`, `toPrecision()`, and `Math.round()`.

**Method Options Compared**

1. **`toFixed()`**: This method returns a string representation of the number with a specified number of digits after the decimal point.
2. **`toPrecision()`**: This method returns a string representation of the number with a specified number of significant digits.
3. **`Math.round()`**: This method returns the largest or smallest integer closest to the given number.

**Pros and Cons**

*   **`toFixed()`**:
    *   Pros: Simple, widely supported, and easy to use. It's also a good choice when you need to format numbers with a fixed number of decimal places.
    *   Cons: Can lead to loss of precision if the input is too large or small for the specified number of decimal places. Also, it uses string formatting, which can be slower than numeric operations.
*   **`toPrecision()`**:
    *   Pros: More flexible and accurate than `toFixed()`, as it considers the significant digits rather than fixed decimal places. It's also a good choice when you need to format numbers with varying precision.
    *   Cons: Less widely supported, can be slower due to string formatting, and may not work well for very large or small input values.
*   **`Math.round()`**:
    *   Pros: Fastest of the three methods, as it performs a simple arithmetic operation. It's also a good choice when you need to round numbers without considering significant digits.
    *   Cons: Less flexible and less accurate than `toFixed()` and `toPrecision()`, as it only rounds to the nearest integer.

**Library Usage**

None of the benchmark tests use any external libraries beyond JavaScript's built-in functions.

**Special JS Features or Syntax**

There are no special JavaScript features or syntax used in this benchmark, making it accessible to a wide range of developers.

**Other Alternatives**

Some alternative methods for rounding or formatting numbers include:

*   Using the `Number` object with the `toExponential()` method: `Number(someFloat).toExponential(4)`
*   Using the ` Intl.NumberFormat` API: `new Intl.NumberFormat('en-US', { maximumFractionDigits: 4 }).format(someFloat)`
*   Using a custom implementation using bitwise operations or multiplication by powers of 10

Note that these alternatives may have different performance characteristics and are not directly comparable to the methods tested in this benchmark.

Related benchmarks:

toFixed vs toPrecision vs Math.round() 2 (version: 0)

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

Created: one year 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 one month ago):