Benchmark: Rounding to precision

Rounding to precision (version: 1)

Comparing performance of: toFixed(4) vs toPrecision(4).toString() vs (Math.round(*10000)/10000).toString(). Please note that Math.floor, Math.trunc and ~~ can't be used for accurate rounding

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

Created: 5 years ago by: Registered User

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Script Preparation code:

var someFloat = 0.987654321;

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest 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 break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark is designed to compare the performance of three different approaches for rounding a floating-point number to a specific precision:

1. `toFixed(4)`
2. `toPrecision(4).toString()`
3. `(Math.round(*10000)/10000).toString()`

These approaches are being tested in various orders and sequences, as evident from the benchmark result.

**Approach 1: `toFixed(4)`**

`toFixed()` is a built-in JavaScript method that rounds a number to a specified precision (in this case, 4 decimal places) and returns the rounded value as a string. The pros of using `toFixed()` include its simplicity and ease of use.

Cons:

* It may not be suitable for all types of numbers or precision requirements.
* It can lead to unexpected results if the original number is too large or too small.

**Approach 2: `toPrecision(4).toString()`**

`toPrecision()` is another built-in JavaScript method that rounds a number to a specified precision (in this case, 4 decimal places) and returns the rounded value as a string. The `toString()` method is called on the result to convert it to a string.

Pros:

* It provides more flexibility than `toFixed()` in terms of precision control.
* It can handle larger numbers or more complex calculations.

Cons:

* It requires an additional call to `toString()`, which may add unnecessary overhead.
* The behavior might vary depending on the browser's implementation.

**Approach 3: `(Math.round(*10000)/10000).toString()`**

This approach uses a manual rounding technique that involves multiplying the number by 10,000 (to shift the decimal point to an integer position), rounding to the nearest integer using `Math.round()`, and then dividing by 10,000 to restore the original precision. The resulting value is converted to a string using `toString()`.

Pros:

* It provides more control over the rounding process.
* It can be used for non-standard precision requirements.

Cons:

* It involves additional arithmetic operations, which may impact performance.
* The approach relies on manual calculations, making it less intuitive and potentially error-prone.

**Other Considerations**

The benchmark also includes test cases with variations in sequence and order, such as `toFixed(4)` followed by `someFloat.t`, which might affect the results. Additionally, some browsers or devices may have different performance characteristics due to factors like cache, hardware acceleration, or JavaScript engine optimization.

**Library Usage**

None of the provided approaches rely on specific libraries. However, if you were to use a library for more advanced rounding or precision calculations, options like `decimal.js` or `Mathjs` might be considered.

**Special JS Features or Syntax**

No special JavaScript features or syntax are being used in these tests. The focus is on evaluating the performance of different rounding techniques.

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