Benchmark: toFixed vs toPrecision vs Math.round() vs Math.floorfast 0

Script Preparation code:

var someFloat = 13.123456789;

Tests:

toFixed(0)
someFloat.toFixed(0);
Math.round()
Math.round(someFloat);
Math.floor fast
~~(someFloat);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toFixed(0)
Math.round()
Math.floor fast

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.67 Safari/537.36

Browser/OS: Chrome 101 on Windows

View result in a separate tab

Test name	Executions per second
toFixed(0)	4452365.5 Ops/sec
Math.round()	3961814.5 Ops/sec
Math.floor fast	12869178.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Purpose**

The provided JSON represents a benchmark that tests how fast different methods are to convert a floating-point number to an integer or a fixed-point representation with a specified precision.

**Tested Options**

There are four options being compared:

1. `toFixed(0)`: Rounds the number to the nearest integer, effectively truncating any decimal part.
2. `Math.round()`: Uses the "banker's rounding" algorithm to round numbers to the nearest even integer.
3. `~~ (someFloat)`: A bitwise trick to convert a floating-point number to an integer by taking the integer part of the number after casting it as an unsigned integer (`~~` is a unary operator in JavaScript that performs a bit-wise AND operation with the maximum value for the specified type, effectively truncating any negative bits).
4. `Math.floor()`: Returns the largest integer less than or equal to the given number.

**Pros and Cons of Each Approach**

* `toFixed(0)`: Pros: easy to read and understand, works well for most cases. Cons: can lead to loss of precision if not used carefully, as it rounds numbers to the nearest integer.
* `Math.round()`: Pros: handles odd numbers correctly, which can be important in some scenarios. Cons: can produce non-integer results due to the "banker's rounding" algorithm, making it less predictable than other options.
* `~~ (someFloat)`: Pros: fast and efficient way to truncate decimal parts. Cons: uses bitwise operations, which may not be as readable or maintainable for all developers. Additionally, this approach can lead to integer overflow issues if the input is very large.
* `Math.floor()`: Pros: simple and straightforward way to get the largest integer less than or equal to a number. Cons: can produce slightly slower results compared to other options due to its more complex implementation.

**Library Usage**

There are no external libraries used in this benchmark, as all operations are built-in JavaScript functions.

**Special JS Features or Syntax**

The `~~` operator is a special case in JavaScript that uses bitwise operations to convert a number to an integer. This trick is not well-documented and may be unfamiliar to some developers, but it's a common pattern used in performance-critical code.

**Other Alternatives**

If you're looking for alternative methods or even more micro-optimizations, here are a few suggestions:

* For `toFixed(0)`, consider using `Number.EPSILON` as the precision value instead of hardcoding 0.
* For `Math.round()`, you could use `Number.EPSILON` as well to make the rounding more precise.
* For `~~ (someFloat)`, if you're concerned about overflow issues, consider using a larger data type or a library function like `BigInt`.
* For `Math.floor()`, you might want to explore other options like `decimal.js` or ` numeral.js` for more precise control over floating-point arithmetic.

Keep in mind that these alternatives may introduce additional complexity or performance overhead, so it's essential to weigh the trade-offs before making changes.

Related benchmarks:

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

Comparing performance of: toFixed(0) vs Math.round() vs Math.floor fast

Created: 2 years ago by: Guest

Jump to the latest result

toFixed(0)

Math.round()

Math.floor fast

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):