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

Script Preparation code:

var someFloat = 0.123456789;

Tests:

toFixed 2 decimals
someFloat.toFixed(2);
toPrecision 2 decimals
someFloat.toPrecision(2)
Math.round 2 decimals
Math.round(someFloat * 100 + Number.EPSILON) / 100

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toFixed 2 decimals
toPrecision 2 decimals
Math.round 2 decimals

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:146.0) Gecko/20100101 Firefox/146.0

Browser/OS: Firefox 146 on Windows

View result in a separate tab

Math.round 2 decimals

994.3M/s

toFixed 2 decimals

21.4M/s

toPrecision 2 decimals

15.5M/s

View exact numbers

Test name	Executions per second
✓ Math.round 2 decimals	994,264,320 Ops/sec
toFixed 2 decimals	21,387,370 Ops/sec
toPrecision 2 decimals	15,494,875 Ops/sec

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.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided JSON represents a benchmark test case that compares the performance of three different methods for rounding a floating-point number: `toFixed`, `toPrecision`, and `Math.round()` with 2 decimal places.

**Test Case Explanation**

The test case consists of three individual test cases, each representing a different method for rounding the same floating-point number, `someFloat`. The test cases are:

1. `toFixed 2 decimals`: This test case measures the performance of using the `toFixed` method to round the number to 2 decimal places.
2. `toPrecision 2 decimals`: This test case measures the performance of using the `toPrecision` method to round the number to 2 decimal places.
3. `Math.round 2 decimals`: This test case measures the performance of using the `Math.round()` function with 2 decimal places.

**Library and Purpose**

In this benchmark, the `Number.EPSILON` property is used in the third test case (`Math.round 2 decimals`). `Number.EPSILON` is a constant that represents the smallest positive value that is different from zero. In JavaScript, when using `Math.round()` with a second argument (the number of decimal places), it takes into account this epsilon value to avoid rounding errors.

**Special JS Feature/Syntax**

In none of the provided code snippets are special JS features or syntax used, such as async/await, generators, or promises. The test cases use standard JavaScript methods and operators.

**Options Compared**

The three options compared in this benchmark are:

* `toFixed` method
* `toPrecision` method
* `Math.round()` function with 2 decimal places

Each of these options has its own pros and cons:

* **`toFixed` method**: This method is simple and easy to use, but it may not be suitable for all cases. It rounds the number to a fixed number of decimal places, which may lead to precision errors if the original value is not exactly representable.
* **`toPrecision` method**: This method provides more control over the rounding process, allowing users to specify the desired number of significant figures. However, it may be slower than `toFixed` due to its more complex implementation.
* **`Math.round()` function with 2 decimal places**: This option is useful when you need to round a number to a specific precision and want to avoid using `toFixed` or `toPrecision`. However, it requires careful handling of edge cases, such as very large numbers.

**Other Considerations**

When choosing between these options, consider the following factors:

* Precision requirements: How many decimal places do you need? Do you need more significant figures?
* Performance: Do you prioritize speed over precision or vice versa?
* Complexity: Are you willing to use a more complex method (e.g., `toPrecision`) for better results?

**Other Alternatives**

If you're looking for alternative methods for rounding numbers in JavaScript, consider:

* Using a library like `decimal.js` for precise arithmetic operations
* Implementing your own rounding algorithm using bitwise operations or other mathematical techniques

Keep in mind that these alternatives may have different trade-offs and requirements compared to the options discussed above.

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

Comparing performance of: `toFixed 2 decimals vs toPrecision 2 decimals vs Math.round 2 decimals`

Created: 4 years ago by: Guest

Go to the latest result

toFixed 2 decimals

toPrecision 2 decimals

Math.round 2 decimals

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() 2 decimal (version: 0)

Comparing performance of: toFixed 2 decimals vs toPrecision 2 decimals vs Math.round 2 decimals

Created: 4 years ago by: Guest

Go to the latest result

toFixed 2 decimals

toPrecision 2 decimals

Math.round 2 decimals

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 2 decimals vs toPrecision 2 decimals vs Math.round 2 decimals`