Benchmark: compate trunc vs parseInt

Script Preparation code:

var num = 2.22 * 100;

Tests:

Trunc
Math.trunc(num);
parseInt
parseInt(num);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Trunc
parseInt

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36

Browser/OS: Chrome 105 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Trunc	5797310.0 Ops/sec
parseInt	5708140.5 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 explanation of what's being tested in this benchmark.

**Benchmark Overview**

The benchmark compares two approaches to truncate or convert a floating-point number to an integer: `Math.trunc()` and `parseInt()`. The test case uses a variable `num` initialized with the value 2.22 * 100, which is equivalent to 222.

**What's being tested?**

* `Math.trunc(num)`: This method truncates the decimal part of the number and returns an integer.
* `parseInt(num)`: This function attempts to convert the string representation of a number to an integer, discarding any decimal part.

**Options Compared**

The benchmark compares two options:

1. **Trunc**: Uses `Math.trunc()` to truncate the decimal part of the number.
2. **parseInt**: Uses `parseInt()` to attempt to convert the string representation of the number to an integer.

**Pros and Cons of Each Approach**

* **Trunc (Math.trunc())**:
	+ Pros: Fast, efficient, and straightforward way to truncate a decimal number to an integer.
	+ Cons: May lose precision if the input is not exactly an integer. In this case, since `num` is 222, no loss of precision occurs.
* **parseInt**:
	+ Pros: Allows for more flexibility in handling non-integer inputs (e.g., strings that start with a decimal number).
	+ Cons: May be slower than `Math.trunc()` due to the overhead of string parsing and conversion. Additionally, it can lead to loss of precision if the input is not a valid integer.

**Library Used**

In this benchmark, no library is explicitly mentioned as being used. However, it's worth noting that `parseInt()` may use internal libraries or functions in JavaScript (e.g., `String.prototype.parseInt()`) to perform its conversion.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax used in this benchmark. It solely relies on standard JavaScript methods and operators.

**Other Alternatives**

If you're interested in exploring alternative approaches, consider the following:

* Using a library like [ numeral.js ](https://numeraljs.com/) which provides precise control over rounding and truncation.
* Implementing a custom function to truncate or convert numbers using bitwise operations (e.g., shifting the decimal point).
* Using other built-in JavaScript methods like `Number()` or `parseFloat()` followed by casting to an integer.

However, for most use cases, `Math.trunc()` is a simple and effective solution that balances performance and precision.

Related benchmarks:

compate trunc vs parseInt (version: 0)

Comparing performance of: Trunc vs parseInt

Created: 2 years ago by: Guest

Jump to the latest result

Trunc

parseInt

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):