Benchmark: string X.Y to ~~ vs parseInt vs Number vs parseFloat vs +0 vs /...

Script Preparation code:

var strA = "1886.47";
var strB = "1886.48";

Tests:

notnot
var res = ~~strA;
parseInt
var res = parseInt(strA);
Number
var res = Number(strA);
parseFloat
var res = parseFloat(strA);
+0
var res = strA + 0;
*1
var res = strA * 1;
-0
var res = strA - 0;
+
var res = +strA;
<<0
var res = strA<<0;
/1
var res = strA / 1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
notnot
parseInt
Number
parseFloat
+0
*1
-0
+
<<0
/1

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Measuring the performance of different methods for handling floating-point numbers in JavaScript is crucial, especially when dealing with decimal literals.

**Benchmarked Methods**

The provided benchmark tests the following methods:

1.  **`~~` (Bitwise NOT)**: This method uses the bitwise NOT operator to truncate the decimal part of a number.
2.  **`parseInt(strA)`**: This method parses the string `strA` as an integer, effectively ignoring its decimal part.
3.  **`Number(strA)`**: This method attempts to parse the string `strA` as a floating-point number.
4.  **`parseFloat(strA)`**: This method parses the string `strA` as a floating-point number and returns it.
5.  **`+0`**: This method adds zero to the literal value of `strA`, which has no effect on its decimal part.
6.  **`*1`**: This method multiplies the literal value of `strA` by one, effectively leaving it unchanged.
7.  **`-0`**: Similar to `+0`, this method subtracts zero from the literal value of `strA`.
8.  **`+strA`**: This method attempts to add the string representation of `strA` as a number.
9.  **`<<0`**: This method shifts the bitwise representation of `strA` left by zero bits, effectively leaving it unchanged.

**Pros and Cons**

Here's a brief overview of each method's performance characteristics:

*   **`~~` (Bitwise NOT)**: Provides the most aggressive truncation of decimal parts but can lead to inaccuracies in certain calculations.
*   **`parseInt(strA)`**: Ignores the decimal part, which is suitable for cases where the decimal value doesn't matter. However, it may not work correctly if `strA` contains a negative sign or leading zeros.
*   **`Number(strA)`** and **`parseFloat(strA)`**: These methods are generally more accurate than `parseInt(strA)`, but still discard any fractional parts.
*   **`+0`**, **`*1`**, and **`-0`**: These methods have negligible effects on the decimal part of `strA`.
*   **`+strA`**: Can lead to incorrect results if `strA` is not a valid number string.
*   **`<<0`**: Shifts the bitwise representation left by zero bits, effectively leaving it unchanged.

**Performance Results**

The benchmark results show that:

*   `~~` provides the fastest execution times for most test cases but may lead to inaccuracies in certain calculations.
*   `parseInt(strA)` and `Number(strA)` have similar performance profiles but discard decimal parts more aggressively than `parseFloat(strA)`.
*   Methods like `+0`, `*1`, `-0`, and `<<0` generally have negligible effects on the execution times.

**Best Practices**

To handle floating-point literals correctly in JavaScript:

*   Use `Number()` or `parseFloat()` when you need to preserve decimal parts.
*   Avoid using `parseInt()` unless you're sure that the input string won't contain fractional parts.
*   Be cautious of methods like `+strA` and use them sparingly.

**Conclusion**

In conclusion, this benchmark highlights the importance of choosing the right method for handling floating-point literals in JavaScript. By understanding the pros and cons of each approach, you can make informed decisions about which method to use in different situations.

Related benchmarks:

string X.Y to ~~ vs parseInt vs Number vs parseFloat vs +0 vs /... (version: 0)

Comparing performance of: notnot vs parseInt vs Number vs parseFloat vs +0 vs *1 vs -0 vs + vs <<0 vs /1

Created: 2 years ago by: Guest

Jump to the latest result

notnot

parseInt

Number

parseFloat

+0

*1

-0

+

<<0

/1

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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