Benchmark: isUpperCase - MeasureThat.net

Tests:

char code
var isUpperCase = c => 'A' <= c && c <= 'Z'; for(c = 0; c < 128; c++) { isUpperCase(String.fromCharCode(c)); }
regex
var isUpperCase = c => /[A-Z]/.test(c); for(c = 0; c < 128; c++) { isUpperCase(String.fromCharCode(c)); }
toLowerCase
var isUpperCase = c => c !== c.toLowerCase(); for(c = 0; c < 128; c++) { isUpperCase(String.fromCharCode(c)); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
char code
regex
toLowerCase

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down what is being tested on the provided JSON.

The test cases are designed to measure the performance of different approaches for determining whether a character is uppercase in JavaScript. There are three individual test cases:

1. **Character Code Approach**: This approach uses the ASCII code of a character to determine if it's uppercase. The script iterates over all possible ASCII codes (0-127) and checks if each one corresponds to an uppercase letter using the `isUpperCase` function.

Pros: This approach is straightforward and easy to understand. It doesn't rely on any external libraries or complex regular expressions.

Cons: This approach has a high number of iterations, which can impact performance for larger ranges of characters. Additionally, it's not as efficient for characters outside the ASCII range (e.g., non-English characters).

2. **Regex Approach**: This approach uses a regular expression to match uppercase letters. The script defines a regex pattern `/[A-Z]/` and checks if each character matches this pattern using the `test()` method.

Pros: Regular expressions can be more efficient than iterating over all possible ASCII codes, especially for larger ranges of characters.

Cons: Regular expressions can be slower due to the overhead of parsing and executing the pattern. Additionally, regex patterns can be less intuitive to read and maintain.

3. **ToLowerCase Approach**: This approach uses the `toLowerCase()` method to check if a character is uppercase by comparing it with its lowercase equivalent.

Pros: This approach is simple and easy to understand. It's also relatively fast since it only involves a single method call.

Cons: This approach assumes that the language supports Unicode, which may not be the case for all platforms or browsers.

In the provided benchmark results, we can see that:

* The `toLowerCase` approach performs the best, with an average of 13204 executions per second.
* The regex approach performs relatively well, with an average of 12415 executions per second.
* The character code approach performs the worst, with an average of 13189 executions per second.

The libraries used in these test cases are:

* None explicitly mentioned in the provided JSON, but it's likely that the `String.fromCharCode()` method is being used to convert ASCII codes to characters.
* No external libraries are required for the regex approach or the `toLowerCase` approach.

As for special JavaScript features or syntax, note that this benchmark doesn't use any specific ES6+ features like arrow functions or template literals. It's written in a more traditional style, with function declarations and string concatenation.

Other alternatives to consider:

* **Other regular expression patterns**: Instead of using the `/[A-Z]/` pattern, you could try other patterns like `[A-Za-z]` or `\p{Lu}` ( Unicode property escape sequence for uppercase letters).
* **Using a more efficient data structure**: If the character range is large, you might consider using a more efficient data structure, such as an array or a trie, to store and query the characters.
* **Caching results**: If the benchmark is run multiple times with the same input, you could consider caching the results to avoid recalculating them unnecessarily.

Keep in mind that these alternatives would require significant changes to the benchmark code and may not provide noticeable performance improvements for smaller character ranges.

Related benchmarks:

isUpperCase (version: 0)

Comparing performance of: char code vs regex vs toLowerCase

Created: 9 years ago by: Guest

Jump to the latest result

char code

regex

toLowerCase

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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