Benchmark: Round to 2 decimal places speed comparisons

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var x = Math.random() * 100;

Tests:

Round floating number using lodash round function
for (var i = 0; i < 1000; i++) { _.round(x, 2); }
Round float number with Math.round
for (var i = 0; i < 1000; i++) { Math.round(x * 100) / 100 }
Round floating number using toFixed()
for (var i = 0; i < 1000; i++) { Number(x.toFixed(2)); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Round floating number using lodash round function
Round float number with Math.round
Round floating number using toFixed()

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark is designed to measure the speed of rounding floating-point numbers in JavaScript. The script preparation code generates a random float value `x` between 0 and 100, which will be used as input for the rounding operations.

**Options Compared**

There are three options being compared:

1. **Lodash's round function**: A popular utility library that provides various mathematical functions.
2. **Math.round**: A built-in JavaScript function to round a number to the nearest integer.
3. **toFixed()**: A method of the Number object in JavaScript, used to convert a floating-point number to a string with a fixed number of decimal places.

**Pros and Cons**

*   Lodash's round function:
    *   Pros: Generally faster than Math.round due to its optimized implementation.
    *   Cons: Requires an external library, which might be slower to load and execute compared to built-in functions.
*   Math.round:
    *   Pros: Fast and lightweight, as it's a built-in function. However, it can lead to rounding errors if the decimal part is not an integer.
    *   Cons: May perform better in some cases than Lodash's round function due to its optimized implementation, but this difference is usually negligible unless dealing with very large datasets.
*   toFixed():
    *   Pros: Can be more readable and maintainable when working with fixed decimal places. However, it might be slower compared to Math.round for simple rounding tasks.

**Library (Lodash)**

The Lodash library provides the round function used in the benchmark. Its purpose is to provide a set of reusable functions that make common programming tasks easier. In this case, the round function is optimized for performance and can handle various data types, including floats.

**Special JS Feature/ Syntax**

None mentioned explicitly.

Now let's consider alternative approaches:

*   **Using built-in rounding methods**: Many programming languages provide built-in rounding functions or methods. For example, in Python, you would use `round()` to round a float.
*   **Manual rounding using binary search**: This method is more complex but can be faster than using an optimized library function like Lodash's round function for very large datasets. However, it requires a good understanding of the algorithm and the specific requirements of your use case.
*   **Using a parallel processing approach**: If you have access to multiple CPU cores or threads, you could divide the data into smaller chunks and perform rounding in parallel using multi-threading techniques.

In conclusion, the provided benchmark is designed to measure the speed of rounding floating-point numbers in JavaScript, comparing three common approaches: Lodash's round function, Math.round, and toFixed(). The choice of approach depends on the specific requirements of your use case, such as performance needs or readability preferences.

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/116.0.0.0 Safari/537.36 Edg/116.0.1938.76

Browser/OS: Chrome 116 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Round floating number using lodash round function	2777.3 Ops/sec
Round float number with Math.round	10121.5 Ops/sec
Round floating number using toFixed()	5012.8 Ops/sec

Related benchmarks:

Round to 2 decimal places speed comparisons (version: 0)

Comparing performance of: Round floating number using lodash round function vs Round float number with Math.round vs Round floating number using toFixed()

Created: one year ago by: Guest

Jump to the latest result

Round floating number using lodash round function

Round float number with Math.round

Round floating number using toFixed()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):