Benchmark: Number vs + vs parseFloat vs Divide

Tests:

Number
var number = Number(Math.random().toString());
Unary +
var unary = +Math.random().toString();
parseFloat
var parse = parseFloat(Math.random().toString());
times by 100 and divide
var divide = Math.round(Math.random() * 100) / 100

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Number
Unary +
parseFloat
times by 100 and divide

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 20 hours ago):

LLMs can make mistakes. Check important info.

The benchmark titled "Number vs + vs parseFloat vs Divide" compares four different methods for converting a random number represented as a string into a numerical format in JavaScript. Below is an explanation of the tested options, their advantages and disadvantages, and some considerations regarding their use.

### Options Compared

1. **Number()**
   - **Benchmark Definition:** `var number = Number(Math.random().toString());`
   - **Description:** This method uses the built-in `Number` function to convert a string representation of a number into a numerical value. It is straightforward and easy to understand.
   - **Pros:** 
     - Easy to use and read.
     - Handles various input formats (e.g., handles strings like "123" and "123.45" well).
   - **Cons:**
     - The overhead of type checking and type coercion may introduce performance concerns in scenarios requiring frequent conversions.

2. **Unary +**
   - **Benchmark Definition:** `var unary = +Math.random().toString();`
   - **Description:** This syntax leverages the unary plus operator (`+`) to convert a string into a number. It is a shorthand approach in JavaScript for numeric coercion.
   - **Pros:**
     - Very concise and potentially faster due to less overhead compared to `Number()`.
     - Familiar to many JavaScript developers as a common idiom for type conversion.
   - **Cons:**
     - Similar to `Number()`, it may not handle all edge cases as expected (e.g., leading/trailing whitespace).

3. **parseFloat()**
   - **Benchmark Definition:** `var parse = parseFloat(Math.random().toString());`
   - **Description:** The `parseFloat` function parses a given string argument and returns a floating-point number.
   - **Pros:**
     - Allows for parsing strings that contain non-numeric characters at the end (e.g., "123.45abc" will return 123.45).
     - More predictable with decimal inputs.
   - **Cons:**
     - More verbose than the unary operator and may also carry additional processing complexity.
     - Like others, may suffer performance issues compared to simpler operations.

4. **Times by 100 and Divide**
   - **Benchmark Definition:** `var divide = Math.round(Math.random() * 100) / 100;`
   - **Description:** This method generates a random number, rounds it, and then divides it to simulate floating-point behavior.
   - **Pros:**
     - Can ensure a limited range of outcomes (in this case, between 0 and 1).
     - Not reliant on string representation, leading to less parsing overhead.
   - **Cons:**
     - Not a direct replacement for converting strings to numbers; instead, it generates numbers within a specific range with a fixed decimal approach.

### Benchmark Results Interpretation

According to the latest benchmark results, the most performant option was "times by 100 and divide," achieving around **6.9 million executions per second**. The unary `+` operator followed closely, achieving approximately **5.4 million executions per second**, making it the second fastest. The `parseFloat()` method was slightly slower at about **4 million executions per second**, while the use of `Number()` was the least performant at nearly **4 million executions per second** as well.

### Other Considerations

- **Performance Variability:** Performance may vary based on JavaScript engine implementations (like V8 in Chrome) and can change with browser updates. Hence, benchmarking on different platforms and versions is crucial.
- **Code Readability vs. Performance:** While the unary `+` operator and `Number()` are both succinct, developers should weigh the trade-offs between performance needs and code maintainability. For instance, while `Number()` is more verbose, it tends to be clearer in intention.
- **Precision Requirements:** In contexts where floating point precision and representation matter greatly (e.g., financial applications), handling the input carefully is paramount. `parseFloat()` has advantages here due to its ability to parse strings with trailing characters.

### Alternatives

There are several alternative approaches to handle conversions in JavaScript:
- **Using `Math.floor()` or `Math.ceil()`**: If strict integer values are required.
- **Custom Parsing Functions**: Building functions that implement specific parsing rules for specialized needs.
- **Integer-based Libraries**: Utilizing libraries like big.js or decimal.js for high-precision numerical handling, though typically overkill for basic conversions.

In conclusion, the given benchmark assesses common methods of number conversion in JavaScript, highlighting performance differences and considerations for developers. Choosing the right method depends on application requirements, performance constraints, and the clarity of the code.

Latest run results:

Run details: (Test run date: 21 hours ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Edg/131.0.0.0

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Number	3984265.5 Ops/sec
Unary +	5404016.5 Ops/sec
parseFloat	4015968.2 Ops/sec
times by 100 and divide	6911009.0 Ops/sec

Related benchmarks:

Number vs + vs parseFloat vs Divide (version: 1)

Comparing performance of: Number vs Unary + vs parseFloat vs times by 100 and divide

Created: 21 hours ago by: Guest

Jump to the latest result

Number

Unary +

parseFloat

times by 100 and divide

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 20 hours ago):