Benchmark: parseInt vs Number vs +

Script Preparation code:

var text = '12';

Tests:

number
console.log(Number(text))
parseint
console.log(parseInt(text))
+
console.log(+text)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
number
parseint
+

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/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Windows

View result in a separate tab

Test name	Executions per second
number	290971.8 Ops/sec
parseint	261051.8 Ops/sec
+	265571.8 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 provided benchmark and explain what's being tested, compared, and analyzed.

**Benchmark Overview**

The benchmark is designed to compare the performance of three different ways to convert a string value "12" into a number in JavaScript: using `Number()`, `parseInt()`, and the unary plus operator (`+`).

**What's Being Tested**

In this benchmark, we're testing the execution time of each conversion method on a specific input value. The test cases are as follows:

1. `console.log(Number(text))`: This tests the `Number()` function.
2. `console.log(parseInt(text))`: This tests the `parseInt()` function.
3. `console.log(+text)`: This tests the unary plus operator (`+`).

**Options Compared**

The benchmark compares the performance of each conversion method:

* `Number()`: Converts a string value to a number using the `Number()` function, which attempts to interpret the string as an integer or float.
* `parseInt()`: Converts a string value to a number using the `parseInt()` function, which only interprets the first sequence of digits in the string and ignores any other characters.
* Unary Plus Operator (`+`): Converts a string value to a number by implicitly applying the unary plus operator, which attempts to interpret the string as an integer.

**Pros and Cons**

Here's a brief summary of each conversion method:

* `Number()`: Pros - Simple and straightforward. Cons - May not work correctly for non-numeric strings or strings with decimal points. In modern JavaScript, it's generally recommended to use `parseFloat()` instead.
* `parseInt()`: Pros - Can handle strings with leading whitespace or other characters before the first digit sequence. Cons - Ignores any characters after the first digit sequence and returns NaN (Not a Number) if no valid digits are found.
* Unary Plus Operator (`+`): Pros - Simple and widely supported. Cons - May not work correctly for non-numeric strings or strings with decimal points.

**Library Usage**

In this benchmark, none of the libraries are explicitly mentioned.

**Special JavaScript Features or Syntax**

There aren't any special JavaScript features or syntax being tested in this benchmark.

**Other Considerations**

When working with string-to-number conversions, consider the following:

* Always validate user input to ensure it's a valid number.
* Use `parseFloat()` instead of `Number()` for more accurate results, especially when dealing with decimal points.
* Be aware of browser quirks and differences in how they handle numeric string conversions.

**Alternative Approaches**

Other ways to convert a string value to a number include:

* Using a regular expression with the `match()` method: `text.match(/^\d+$/)[0]`
* Using a library like Lodash's `parseNumber()`: `_lib.parseNumber(text)`
* Implementing a custom parsing function using regex and/or arithmetic operations.

Keep in mind that these alternatives might not be as simple or efficient as the original benchmark, but they can provide more flexibility or control over the conversion process.

Related benchmarks:

parseInt vs Number vs + (version: 0)

Comparing performance of: number vs parseint vs +

Created: 4 years ago by: Guest

Jump to the latest result

number

parseint

+

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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