Benchmark: replace vs charAT for Capitalise helper

Script Preparation code:

var str = 'foo bar baz';
var capstr = 'Foo bar baz';
var noop = Function.prototype;

Tests:

character index
if (str.charAt(0).toUpperCase() + str.slice(1) === capstr) noop();
charAt()
if (str.replace(/^\w/, c => c.toUpperCase()) === capstr) noop();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
character index
charAt()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.54 Safari/537.36

Browser/OS: Chrome 94 on Windows

View result in a separate tab

Test name	Executions per second
character index	2507824.0 Ops/sec
charAt()	1710178.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**What is being tested?**

The benchmark measures the performance of two different approaches to capitalize the first character of a string:

1. Using `str.charAt(0).toUpperCase() + str.slice(1)`
2. Using `str.replace(/^\\w/, c => c.toUpperCase())`

The goal is to compare these two methods and determine which one is faster.

**Options compared**

The benchmark compares two options:

* **charAt()**: Uses the `charAt()` method to get the first character of the string, converts it to uppercase using `toUpperCase()`, and then concatenates the rest of the original string.
* **replace() with regex**: Uses a regular expression (`^\\w`) to match the first word (or character) in the string, replaces it with its uppercase equivalent using an arrow function, and returns whether the modified string matches the target capitalized string.

**Pros and cons**

Here are some pros and cons of each approach:

* **charAt()**: Pros:
	+ Can be faster since it uses a native method that's optimized for performance.
	+ Easier to understand and maintain.
* Cons:
	+ May not handle edge cases (e.g., strings with no characters) as well as other methods.
* **replace() with regex**: Pros:
	+ More flexible, handling multiple word boundaries (not just the first character).
	+ Can be used for more complex string manipulation tasks.
* Cons:
	+ May be slower due to the overhead of compiling a regular expression.
	+ Less readable and maintainable than `charAt()`.

**Library**

There is no explicit library mentioned in the benchmark definition or test cases. However, it's likely that some standard JavaScript libraries (e.g., Lodash) might be used indirectly.

**Special JS feature or syntax**

This benchmark doesn't use any special JavaScript features or syntax beyond what's considered standard by most modern browsers.

**Other alternatives**

If you were to implement this benchmark with a different approach, you could consider:

* Using `str.substring(0, 1).toUpperCase()` instead of `charAt()`.
* Using `String.prototype.replace()` with a callback function instead of an arrow function.
* Implementing a custom, in-house solution for string capitalization.

Keep in mind that any alternative implementation would need to be tested and validated to ensure it provides comparable performance to the original benchmark.

Related benchmarks:

replace vs charAT for Capitalise helper (version: 0)

Compare methods for testing string's beggining character.

Comparing performance of: character index vs charAt()

Created: 3 years ago by: Guest

Jump to the latest result

character index

charAt()

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):