Benchmark: number vs typeof

Tests:

isNumber
Number.isFinite(Math.random())
typeof
typeof (Math.random()) === 'number'

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
isNumber
typeof

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:141.0) Gecko/20100101 Firefox/141.0

Browser/OS: Firefox 141 on Windows

View result in a separate tab

Test name	Executions per second
isNumber	564556032.0 Ops/sec
typeof	672755520.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided benchmark.

**Main Question:** The main question being asked is whether `typeof` returns `'number'` when passed the result of `Math.random()`, versus checking if the result is a finite number using `Number.isFinite()`.

**Options Compared:**

1. **typeof**: This option checks if the type of the value (in this case, `Math.random()`) is `'number'`. The behavior of `typeof` can be different from what one might expect, as it returns the type of the variable at compile-time, not runtime.
2. **Number.isFinite()**: This option checks if the value (in this case, `Math.random()`) is a finite number.

**Pros and Cons:**

*   **typeof**:
    *   Pros:
        *   Generally faster than using `Number.isFinite()` since it can be optimized by the JavaScript engine.
        *   More straightforward to understand, as it directly returns the type of the value.
    *   Cons:
        *   May not work as expected for some edge cases, such as NaN (Not a Number) or infinity values.
*   **Number.isFinite()**:
    *   Pros:
        *   More accurate and reliable than `typeof`, especially when dealing with non-finite numbers.
        *   Provides a more explicit way to check if a value is finite.
    *   Cons:
        *   Generally slower than `typeof` due to its additional checks.

**Other Considerations:**

*   The choice between these two options largely depends on the specific use case and performance requirements. If speed is critical, using `typeof` might be a better option. However, if accuracy and reliability are more important, `Number.isFinite()` should be preferred.
*   Another factor to consider is that `typeof` can return `'number'` for NaN or infinity values, which may not be desirable in all cases.

**Library Usage:**

There is no specific library being used in this benchmark. The functions and methods mentioned (`Math.random()`, `Number.isFinite()`) are built-in JavaScript functions.

**Special JS Features/Syntax:**

There is no mention of any special JavaScript features or syntax in the provided code or explanation. If there were any, it would be worth explaining them to provide a better understanding of the benchmark.

**Benchmark Preparation Code and Definition:**

Since there's no script preparation code or detailed HTML preparation code provided, we can only focus on the provided benchmark definition and test cases.

Related benchmarks:

number vs typeof (version: 0)

Comparing performance of: isNumber vs typeof

Created: 2 years ago by: Guest

Jump to the latest result

isNumber

typeof

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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