Benchmark: toFixed vs Math.round()

Script Preparation code:

var someFloat = 0.123456789;

Tests:

Number(toFixed(2))
Number(someFloat.toFixed(4));
Math.round(*100)/100
Math.round(someFloat*100)/100;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Number(toFixed(2))
Math.round(*100)/100

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4293.0 Safari/537.36

Browser/OS: Chrome 88 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Number(toFixed(2))	1403795.4 Ops/sec
Math.round(*100)/100	3971847.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months 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 compares two approaches to round or format numbers: `toFixed()` and `Math.round()`. The goal is to determine which approach is faster for specific use cases.

**Options Compared**

1. **`toFixed(4)`**: This method rounds a number to the specified number of decimal places using the "fixed" rounding mode.
2. **`Math.round(*100)/100`**: This method multiplies the input number by 100, rounds it to the nearest integer using `Math.round()`, and then divides the result by 100.

**Pros and Cons**

* **`toFixed(4)`**:
	+ Pros: Easy to read and understand, produces a formatted string with a specified number of decimal places.
	+ Cons: May lead to precision issues if not careful, can be slower due to the rounding mode.
* **`Math.round(*100)/100`**:
	+ Pros: Faster than `toFixed(4)` for most use cases, as it avoids unnecessary decimal place manipulation.
	+ Cons: Less readable and understandable than `toFixed(4)`, may produce unexpected results if not used carefully.

**Library Usage**

There is no explicit library usage in the provided benchmark code. However, it's worth noting that `Math.round()` is a built-in JavaScript function, which means it doesn't rely on any external libraries.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes being used in this benchmark (e.g., async/await, generators, promises). The code is straightforward and focused on comparing two numerical rounding methods.

**Other Alternatives**

For those interested in exploring alternative approaches to round numbers in JavaScript:

* **`Number.EPSILON`**: This property represents the smallest difference that can be detected between two numbers. You can use it to determine if a number is close enough to zero, allowing for more flexible rounding.
* **`Decimal.js` library**: A popular library for performing decimal arithmetic and rounding numbers with high precision.

Keep in mind that these alternatives might not be as straightforward or efficient as the built-in `Math.round()` function, but they can provide more flexibility and control over numerical operations.

Related benchmarks:

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

Comparing performance of: Number(toFixed(2)) vs Math.round(*100)/100

Created: 4 years ago by: Guest

Jump to the latest result

Number(toFixed(2))

Math.round(*100)/100

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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