Benchmark: startsWith vs inlcudes

Tests:

startsWith
const str = "Прицеп полуприцеп"; str.startsWith("Прицеп по");
includes
const str = "Прицеп полуприцеп"; str.includes("полуприцеп");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith
includes

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark is defined as follows:

* Two test cases are defined: `startsWith` and `includes`.
* Each test case uses a JavaScript string literal with a specific substring.

**Test Cases**

1. **startsWith**
	* The test case checks if the string `"Прицеп полуприцеп"` starts with the substring `"прицеп по"`. If it does, the benchmark measures the performance of the `startsWith` method.
2. **includes**
	* The test case checks if the string `"Прицеп полуприцеп"` includes the substring `"полуприцеп"`. If it does, the benchmark measures the performance of the `includes` method.

**Options Compared**

The benchmark compares two options:

1. **startsWith**: A method that returns a boolean indicating whether the string starts with the specified substring.
2. **includes**: A method that returns a boolean indicating whether the string includes the specified substring.

**Pros and Cons**

* **startsWith**
	+ Pros:
		- More efficient than `includes` for certain cases, since it stops searching as soon as it finds the match.
		- Can be faster for shorter substrings.
	+ Cons:
		- May be slower for longer substrings, since it still needs to search the entire string.
* **includes**
	+ Pros:
		- Can be more readable and intuitive than `startsWith`, since it explicitly indicates that the substring is part of the original string.
		- May be faster for longer substrings, since it doesn't need to stop searching as soon as it finds a match.
	+ Cons:
		- Generally slower than `startsWith` for shorter substrings.

**Library and Special JS Features**

There are no libraries used in this benchmark. However, the test cases use JavaScript syntax that is widely supported across different browsers.

**Other Considerations**

The benchmark measures the performance of these two methods on a specific string literal, which may not be representative of real-world usage patterns. In particular:

* The string `"Прицеп полуприцеп"` contains non-ASCII characters, which may affect the performance of certain browsers or libraries.
* The test cases use hardcoded substrings, which may not cover all possible edge cases.

**Alternatives**

There are other methods that could be used instead of `startsWith` and `includes`, such as:

* **String.prototype.indexOf()**: A method that returns the index of the first occurrence of the substring in the string. This can be faster than `startsWith` but slower than `includes`.
* **Regular expressions**: A way to match patterns in strings using a regular expression engine. This can be more flexible than `startsWith` and `includes` but often slower.

Overall, the benchmark provides a simple and concise way to compare the performance of two common string manipulation methods in JavaScript.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.27 Safari/537.36

Browser/OS: Chrome 96 on Linux

View result in a separate tab

Test name	Executions per second
startsWith	70152592.0 Ops/sec
includes	34788616.0 Ops/sec

Related benchmarks:

startsWith vs inlcudes (version: 0)

Comparing performance of: startsWith vs includes

Created: 3 years ago by: Guest

Jump to the latest result

startsWith

includes

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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