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

Script Preparation code:

var someFloat = 0.123456789;

Tests:

toFixed(4)
Number(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:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**What is being tested?**

The provided JSON represents a benchmark test that compares three different approaches to convert a floating-point number to a string with a fixed number of decimal places:

1. `toFixed()`
2. `toPrecision()`
3. `Math.round()` followed by some arithmetic operations and then converting the result back to a string

**Options compared**

The options being compared are:

* `toFixed(4)`: Converts the float to a string with exactly 4 decimal places.
* `toPrecision(4).toString()`: Converts the float to a string using `toPrecision()` which allows for more flexibility, and then explicitly converts the result to a string using `toString()`.
* `(Math.round(*10000)/10000).toString()`: Rounds the float to 4 decimal places using `Math.round()` followed by some arithmetic operations (`*10000` and `/10000`) and then converts the result back to a string.

**Pros and Cons of each approach**

1. **toFixed(4)**:
	* Pros: Simple, well-established method that provides precise control over the number of decimal places.
	* Cons: May not work correctly with very large or very small numbers, as it uses fixed-size buffers to store the decimal representation.
2. **toPrecision(4).toString()**:
	* Pros: More flexible than `toFixed()` and can handle a wider range of numbers, including very large or very small ones.
	* Cons: Requires explicit conversion to a string using `toString()`, which may add unnecessary overhead.
3. **(Math.round(*10000)/10000).toString()**:
	* Pros: Provides more control over the rounding process than `toFixed()` and can be optimized for performance by avoiding explicit conversions to strings.
	* Cons: Requires more arithmetic operations, which may introduce additional overhead.

**Library usage**

None of the benchmark testcases use any libraries.

**Special JS features or syntax**

The benchmark tests do not use any special JavaScript features or syntax beyond what is considered standard. They are designed to be as straightforward and easy to understand as possible.

**Other alternatives**

There are other approaches that could be used to convert floating-point numbers to strings with a fixed number of decimal places, such as:

* Using the `Number.prototype.toLocaleString()` method (if supported by the browser)
* Implementing custom conversion logic using bitwise operations or other low-level techniques
* Using specialized libraries like ICU or locale-aware formatting tools

However, these alternatives are not included in this benchmark test and are likely to be less well-supported across different browsers and platforms.

Related benchmarks:

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

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

Created: 7 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>

Fastest: N/A

Slowest: N/A

No previous run results

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