Benchmark: + operator vs parseInt vs Number addition

Script Preparation code:

var str = "42.034";

Tests:

+ operator
var res = +str
parseInt
var res = parseInt(str)
Number
var res = Number(str)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
+ operator
parseInt
Number

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:135.0) Gecko/20100101 Firefox/135.0

Browser/OS: Firefox 135 on Linux

View result in a separate tab

Test name	Executions per second
+ operator	898934720.0 Ops/sec
parseInt	998738944.0 Ops/sec
Number	979487936.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark you're examining compares three different methods of converting a string representing a number into a JavaScript number. The methods being tested are:

1. **Using the `+` operator (Unary plus)**: This method is a shorthand way to convert a string to a number. By placing a `+` sign before the string, JavaScript attempts to convert the string to a numerical value.

2. **Using `parseInt` function**: This function reads a string argument and returns an integer of the specified radix (base). If no radix is provided, it defaults to base 10 if the string doesn't start with '0x' or '0', and to base 16 if it does.

3. **Using the `Number` function**: This function converts its argument to a number, following standard conversion rules for JavaScript.

### Pros and Cons of Each Approach

1. **+ Operator**
   - **Pros**:
     - Simple and concise syntax.
     - Typically performs very well in JavaScript engines due to being a native operation.
   - **Cons**:
     - Can be less explicit than using `parseInt` or `Number`, potentially leading to confusion for those unfamiliar with JavaScript. Some might not recognize that it's performing a conversion.

2. **parseInt**
   - **Pros**:
     - Offers control over the radix, allowing you to specify the base (e.g., 2 for binary, 10 for decimal).
     - Useful when you specifically want to extract an integer from a string, especially if the string has non-numeric characters.
   - **Cons**:
     - Can yield unexpected results if the string doesn't represent a valid number (e.g., leading non-numeric characters can cause issues).
     - Only parses integers, meaning it won't convert floating-point numbers accurately, as fractions will be truncated.

3. **Number**
   - **Pros**:
     - Provides a clear and explicit intent that the value should be converted to a number.
     - Handles both integers and floating-point values effectively.
   - **Cons**:
     - May throw a `NaN` (Not-a-Number) result for clearly invalid strings, which could necessitate additional error handling.

### Additional Considerations
- The benchmark results show that `parseInt` has the highest performance metrics in terms of executions per second, followed closely by the `Number` function, with the `+` operator trailing behind.
- This may suggest that while all three methods perform similarly in many use cases, optimizations in the underlying JavaScript engine may favor the `parseInt` method for string parsing tasks in this specific testing environment.

### Other Alternatives
Other methods that could convert strings to numbers in JavaScript include `parseFloat`, which is similar to `parseInt` but converts strings to floating-point numbers instead. This would come in handy when dealing with decimal numbers specifically, but would not be covered in this benchmark.

Backend solutions or libraries in Python, such as `int()` or `float()`, may offer different conversion techniques and behaviors, but those are outside the scope of this JavaScript benchmark.

Overall, the benchmark provided a clear comparative analysis of the string to number conversion methods in JavaScript, helping developers make informed choices based on performance and correctness for specific tasks.

Related benchmarks:

+ operator vs parseInt vs Number addition (version: 1)

Comparing performance of: + operator vs parseInt vs Number

Created: one year ago by: Guest

Jump to the latest result

+ operator

parseInt

Number

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):