Benchmark: + vs Number, with 100k numbers

Script Preparation code:

var arr = [];

for (let i = 0; i < 100000; i++) {
    arr.push(`${i}`)
    i++
}

Tests:

Class cast
arr.map(Number)
+Cast
arr.map(x => +x)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Class cast
+Cast

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser/OS: Chrome 119 on Windows

View result in a separate tab

Test name	Executions per second
Class cast	1588.6 Ops/sec
+Cast	1462.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what's being tested in this JavaScript microbenchmark.

**Benchmark Definition**

The benchmark definition is represented by two test cases:

1. `arr.map(Number)`: This code casts an array of strings to numbers using the built-in `Number()` function.
2. `arr.map(x => +x)`: This code uses a shorthand syntax to cast an array of strings to numbers, where `+` is used as the function argument.

**What are we comparing?**

We're comparing the performance of these two approaches for several reasons:

*   **Efficiency**: How quickly do each approach execute?
*   **Readability**: Which approach is more readable or easier to understand?
*   **Maintainability**: Are there any potential issues with maintaining or extending this code in the future?

**Pros and Cons**

Here's a brief summary of the pros and cons for each approach:

### arr.map(Number)

Pros:
*   More concise and readable
*   Easy to implement and maintain

Cons:
*   May require additional libraries or dependencies (e.g., `number` polyfill)
*   Some older browsers may not support this syntax

### arr.map(x => +x)

Pros:
*   Can be used in older browsers that don't support the shorthand syntax
*   Allows for more control over the casting process

Cons:
*   Less readable and less concise than the first approach
*   May require more code to achieve the same result

**Library Usage**

In this benchmark, there is no specific library being used. However, if you were to add a library, it would likely be something like `number` or `lodash`, which provide utility functions for working with numbers.

**Special JS Features/Syntax**

Both test cases use the following special JavaScript features:

*   **Arrow Functions**: Used in `arr.map(x => +x)`.
*   **Function Arguments**: Used in both test cases to specify the casting function.

These features are supported by most modern browsers, but if you need to support older browsers, you may need to add additional polyfills or transpilers.

**Alternatives**

If you're interested in exploring alternative approaches or optimizations, here are a few options:

*   **Using `parseInt()`**: Instead of casting strings to numbers, you can use `parseInt()` with an optional second argument ( radix) to specify the base of the number. For example: `arr.map(x => parseInt(x, 10))`
*   **Using ` parseFloat()`**: Similar to `parseInt()`, but returns a floating-point number instead of an integer.
*   **Avoiding Casting**: Consider using data types that are already numbers (e.g., `let arr = [1.23, 4.56]`) to avoid the need for casting altogether.

Keep in mind that these alternatives may have different performance characteristics or implications for maintainability and readability.

Related benchmarks:

+ vs Number, with 100k numbers (version: 0)

Comparing performance of: Class cast vs +Cast

Created: one year ago by: Guest

Jump to the latest result

Class cast

+Cast

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):