Benchmark: Capitalize - MeasureThat.net

Tests:

1
function capitalizeFirstLetter(string) { return string.charAt(0).toUpperCase() + string.slice(1); } capitalizeFirstLetter('string');
2
function capitalizeFirstLetter(string) { return string.replace(/^./, string[0].toUpperCase()); } capitalizeFirstLetter('string');
3
function capitalizeFirstLetter(string) { return string[0].toUpperCase() + string.slice(1); } capitalizeFirstLetter('string');
4
String.prototype.capitalizeFirstLetter = function() { return this.charAt(0).toUpperCase() + this.slice(1); } 'string'.capitalizeFirstLetter();
5
function capitalizeFirstLetter(s) { return s[0].toUpperCase() + s.substr(1); } capitalizeFirstLetter('string');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
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3
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5

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a set of JavaScript microbenchmarks designed to measure the performance of different string capitalization methods in various browsers and environments.

**Benchmark Definition**

The benchmark definition is represented by the `Name` field, which in this case is "Capitalize". The description is empty (`null`), indicating that there is no detailed explanation for this benchmark. The script preparation code and HTML preparation code are also empty (`null`), suggesting that these fields might be used to provide additional context or setup instructions.

**Test Cases**

There are five test cases, each representing a different implementation of the string capitalization method:

1. **Using `charAt()` and `toUpperCase()`**: This implementation uses the `charAt()` method to extract the first character of the string and the `toUpperCase()` method to convert it to uppercase.
2. **Using `replace()` with regular expression**: This implementation uses the `replace()` method with a regular expression (`^.`) to match the first character of the string and replace it with its uppercase equivalent.
3. **Using `slice()` and `toUpperCase()`**: This implementation uses the `slice()` method to extract the substring after the first character and the `toUpperCase()` method to convert it to uppercase, then concatenates the results.
4. **Adding a prototype method to String**: This implementation defines a new prototype method called `capitalizeFirstLetter` on the String object, which takes no arguments but returns the capitalized string.
5. **Using `substr()`**: This implementation uses the `substr()` method to extract the substring after the first character and converts it to uppercase using the `toUpperCase()` method.

**Library Usage**

None of the test cases use any external libraries or dependencies.

**Special JavaScript Features**

Some features used in these implementations include:

* **Regular expressions (regex)**: Used in implementation 2 to match the first character of the string.
* **Prototype methods**: Used in implementation 4 to add a new method to the String object.

**Pros and Cons of Different Approaches**

Here's a brief analysis of each implementation:

1. Using `charAt()` and `toUpperCase()`: This approach is straightforward but may be slower due to the overhead of function calls.
2. Using `replace()` with regex: This approach is efficient but may have performance issues if not implemented correctly, as it involves regular expression processing.
3. Using `slice()` and `toUpperCase()`: This approach has similar efficiency characteristics to implementation 1 but uses more memory allocation and copying.
4. Adding a prototype method to String: This approach modifies the original String object, which can be useful for performance-critical code. However, it may introduce unexpected side effects if not used carefully.
5. Using `substr()`: Similar to implementation 3, this approach has similar efficiency characteristics but uses more memory allocation and copying.

**Other Alternatives**

Some alternative approaches could be explored:

* **Using a custom function**: Instead of using the built-in string methods, a custom function could be created to perform the capitalization operation. This might provide better performance due to reduced overhead.
* **Using an optimized regex engine**: If the `replace()` approach is used, an optimized regex engine like PCRE (Portable C Regular Expressions) or UAX (Unicode Algorithm for Abstract Character Classification) might provide better performance.

Keep in mind that these alternatives would depend on specific requirements and use cases.

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36 Edg/122.0.0.0

Browser/OS: Chrome 122 on Windows

View result in a separate tab

Test name	Executions per second
1	88101736.0 Ops/sec
2	20666122.0 Ops/sec
3	88998792.0 Ops/sec
4	4939369.0 Ops/sec
5	90013680.0 Ops/sec

Related benchmarks:

Capitalize (version: 0)

Comparing performance of: 1 vs 2 vs 3 vs 4 vs 5

Created: 7 years ago by: Guest

Jump to the latest result

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5

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):