Benchmark: startsWith & endsWith vs test

Script Preparation code:

var text = '/* Benchmark name and description  */';

Tests:

startsWith & endsWith
if (text.startsWith('/*') && text.endsWith('*/')) { }
test
if (/^\/\*.*\*\/$/.test(text)) { }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith & endsWith
test

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the JavaScript microbenchmark on MeasureThat.net.

**Benchmark Overview**

The benchmark is designed to compare two approaches for checking if a string starts with and ends with a specific substring: using the `startsWith()` and `endsWith()` methods (Example 1) versus using a regular expression (`/regex/` pattern). The test aims to measure which approach is faster in JavaScript.

**Options Compared**

The benchmark compares the following options:

1. **Using `startsWith()` and `endsWith()` methods**: This method uses the built-in `startsWith()` and `endsWith()` methods of the String prototype, which check if a string starts with or ends with a specific substring, respectively.
2. **Using a regular expression (`/regex/` pattern)**: This method uses a regular expression to match the start and end patterns.

**Pros and Cons**

Here are some pros and cons for each approach:

* Using `startsWith()` and `endsWith() methods`:
	+ Pros: More readable, easier to understand, and more efficient (since these methods are implemented in native code).
	+ Cons: Not all browsers support these methods, and their performance may vary.
* Using a regular expression (`/regex/` pattern):
	+ Pros: More versatile, can be used with any language, and works in older browsers that don't support `startsWith()` and `endsWith()`.
	+ Cons: Less readable, more complex to write and maintain, and slower (since the regex engine has overhead).

**Library Used**

In this benchmark, no specific library is mentioned. However, some libraries like RegEx.js or regex-string can be used for regular expression matching.

**Special JavaScript Features/Syntax**

No special JavaScript features or syntax are being tested in this benchmark. Both approaches use standard JavaScript syntax and methods.

**Other Alternatives**

Other alternatives to compare might include:

* Using `String.prototype.match()` with a specific pattern.
* Using `RegExp.test()` with a specific pattern.
* Using a third-party library like `regex-string` for regular expression matching.

It's worth noting that the choice of approach depends on the specific use case and requirements. If readability and maintainability are crucial, using `startsWith()` and `endsWith() methods` might be a better option. However, if versatility and performance are more important, using a regular expression (`/regex/` pattern) might be a better fit.

**Benchmark Preparation Code**

The benchmark preparation code is:
```javascript
var text = '/* Benchmark name and description */';
```
This creates a simple string variable `text` that will be used as the input for the benchmarks. The actual content of the variable is left blank to allow users to modify it.

**Individual Test Cases**

There are two test cases:

1. "startsWith & endsWith"
	* Benchmark Definition: `if (text.startsWith('/*') && text.endsWith('*/')) { }`
2. "test"
	* Benchmark Definition: `if (/^\\/\\*.*\\*\\/$/.test(text)) { }`

These test cases simply check if the input string `text` starts with and ends with a specific substring (`'/*'` and `'*/'`, respectively).

**Latest Benchmark Results**

The latest benchmark results show that:

* "startsWith & endsWith" is faster (with 226,736,560 executions per second).
* "test" is slower (with 209,835,000 executions per second).

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0

Browser/OS: Firefox 102 on Linux

View result in a separate tab

Test name	Executions per second
startsWith & endsWith	22673660.0 Ops/sec
test	20983500.0 Ops/sec

Related benchmarks:

startsWith & endsWith vs test (version: 0)

Comparing performance of: startsWith & endsWith vs test

Created: 6 years ago by: Guest

Jump to the latest result

startsWith & endsWith

test

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):