Benchmark: parseInt vs toFixed vs tilde vs bitwise

HTML Preparation code:

<div id="num"></div>

Script Preparation code:

var el = document.getElementById('num');

Tests:

parseInt
var decimal = 30.0; for (var i = 0; i < 10000; i++) { decimal += (i / 1000); el.innerHTML = parseInt(decimal, 10); }
toFixed
var decimal = 30.0; for (var i = 0; i < 10000; i++) { decimal += (i / 1000); el.innerHTML = decimal.toFixed(); }
Tilde
var decimal = 30.0; for (var i = 0; i < 10000; i++) { decimal += (i / 1000); el.innerHTML = ~~decimal; }
Bitwise
var decimal = 30.0; for (var i = 0; i < 10000; i++) { decimal += (i / 1000); el.innerHTML = decimal | 0; }
Math.round
var decimal = 30.0; for (var i = 0; i < 10000; i++) { decimal += (i / 1000); el.innerHTML = Math.round(decimal); }
Math.trunc
var decimal = 30.0; for (var i = 0; i < 10000; i++) { decimal += (i / 1000); el.innerHTML = Math.trunc(decimal); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
parseInt
toFixed
Tilde
Bitwise
Math.round
Math.trunc

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0

Browser/OS: Firefox 115 on Windows 8

View result in a separate tab

Test name	Executions per second
parseInt	34.9 Ops/sec
toFixed	31.0 Ops/sec
Tilde	31.1 Ops/sec
Bitwise	35.4 Ops/sec
Math.round	35.5 Ops/sec
Math.trunc	35.3 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**What is being tested?**

The benchmark is comparing four different methods to format or manipulate decimal numbers:

1. `parseInt`
2. `toFixed`
3. "Tilde" (which is actually the bitwise NOT operator ~, but it can be used as a shorthand for rounding)
4. Bitwise operation (`decimal | 0`)
5. `Math.round` and `Math.trunc`

The test case is creating a decimal number and repeatedly adding a small increment to it, updating an HTML element with the current value using each of these methods.

**Options compared**

* `parseInt`: converts the decimal number to an integer
* `toFixed`: formats the decimal number as a fixed-point string (e.g., "30.0")
* "Tilde" (`~~`): uses the bitwise NOT operator to round down to the nearest whole number
* Bitwise operation (`decimal | 0`): uses the bitwise AND operator with 0 to truncate the decimal part
* `Math.round`: rounds the decimal number to the nearest integer
* `Math.trunc`: truncates the decimal number to the nearest whole number (similar to "Tilde" but using a built-in function)

**Pros and cons of each approach**

* `parseInt`: simple, fast, but may lose precision due to rounding errors
* `toFixed`: more precise than `parseInt`, but can be slower due to string formatting overhead
* "Tilde" (`~~`): fast, but can produce unexpected results if the input is not an integer
* Bitwise operation (`decimal | 0`): very fast, but may be less readable and more prone to errors
* `Math.round`: more precise than `parseInt`, but still rounds down
* `Math.trunc`: similar to "Tilde" but using a built-in function, which can be faster and more reliable

**Other considerations**

* The use of bitwise operations is an unusual approach for formatting decimal numbers. While it may be fast, it's not the most readable or maintainable solution.
* The use of `~~` as a shorthand for rounding down is also uncommon. It's better to use `Math.trunc` or `Math.round` instead.

**Library**

None mentioned in this benchmark. However, note that some browsers (like Chrome) have built-in functions like `toFixed` and `Math.round`/`Math.trunc`, which can simplify the implementation.

**Special JS feature/syntax**

None explicitly mentioned in this benchmark.

Related benchmarks:

parseInt vs toFixed vs tilde vs bitwise (version: 0)

Comparing performance of: parseInt vs toFixed vs Tilde vs Bitwise vs Math.round vs Math.trunc

Created: 5 years ago by: Guest

Jump to the latest result

parseInt

toFixed

Tilde

Bitwise

Math.round

Math.trunc

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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