Benchmark: birirbibir - MeasureThat.net

HTML Preparation code:

<div></div>

Script Preparation code:

window.regexStart = /^test/;
window.regexEnd = /test$/;
window.match = 'test';
window.matchLength = window.match.length;
var data = window.data = [];
const possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
var TOTAL_STRINGS = window.TOTAL_STRINGS = 100000;

function getRandomInt(max) {
  return Math.floor(Math.random() * max);
}

function makeRandomString(len) {
  var text = "";
  for( var i=0; i < len; i++ ) {
    text += possible.charAt(getRandomInt(possible.length));
  }
  return text;
}

while (data.length < TOTAL_STRINGS) {
  data.push(makeRandomString(getRandomInt(20)));
}

Tests:

regex start
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var regex = window.regexStart; while (x < TOTAL_STRINGS) { const str = data[x]; regex.test(str); x += 1; }
startsWith
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.match; while (x < TOTAL_STRINGS) { const str = data[x]; str.startsWith(match); x += 1; }
regex end
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var regex = window.regexEnd; while (x < TOTAL_STRINGS) { const str = data[x]; regex.test(str); x += 1; }
endsWith
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.match; while (x < TOTAL_STRINGS) { const str = data[x]; str.endsWith(match); x += 1; }
indexOf start
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.match; while (x < TOTAL_STRINGS) { const str = data[x]; str.indexOf(match) === 0; x += 1; }
indexOf end
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.match; var length = window.matchLength; while (x < TOTAL_STRINGS) { const str = data[x]; str.indexOf(match) === str.length - length; x += 1; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex start
startsWith
regex end
endsWith
indexOf start
indexOf end

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.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The benchmark in question is a fork of an existing benchmark, which compares the performance of different string matching methods: `indexOf` with start and end positions, `startsWith`, `endsWith`, `regexStart`, and `regexEnd`.

**Tested Methods**

The benchmark tests six different methods:

1. **`indexOf(start)`**: Tests the method `str.indexOf(match) === 0`. This checks if the matched substring is at the beginning of the original string.
2. **`startsWith(match)`**: Tests the method `str.startsWith(match)`. This checks if the original string starts with the matched substring.
3. **`endsWith(match)`**: Tests the method `str.endsWith(match)`. This checks if the original string ends with the matched substring.
4. **`regexStart`**: Tests the method `regex.test(str)`. This uses a regular expression to match the entire string.
5. **`regexEnd`**: Tests the method `regex.test(str)`, but with a different regular expression that only matches at the end of the string.
6. **`indexOf(end)`**: Tests the method `str.indexOf(match) === str.length - length`. This checks if the matched substring is at the end of the original string, given the length of the matched substring.

**Comparison and Performance**

The benchmark measures the number of executions per second for each method on a dataset of 100,000 random strings. The results are:

* `indexOf(end)`: approximately 13144 executions per second
* `indexOf(start)`: approximately 13066 executions per second
* `startsWith`: approximately 507 executions per second
* `endsWith`: approximately 573 executions per second
* `regexStart`: approximately 700 executions per second
* `regexEnd`: approximately 670 executions per second

**Interpretation**

The results suggest that:

* `indexOf(end)` is the fastest method, followed closely by `indexOf(start)`.
* `startsWith` and `endsWith` are significantly slower than the other methods.
* The regular expression-based methods (`regexStart` and `regexEnd`) are relatively fast, but not as fast as the `indexOf` methods.

**Conclusion**

The benchmark highlights the importance of choosing the right string matching method for your specific use case. While `indexOf(end)` is the fastest method in this scenario, other methods may be more suitable depending on your requirements. Regular expression-based methods can offer a good balance between performance and expressiveness, but may require more overhead than simpler methods like `startsWith` or `endsWith`.

Related benchmarks:

birirbibir (version: 0)

fork of https://www.measurethat.net/Benchmarks/Show/975/11/regex-vs-indexof-vs-startswith-vs-substr

Comparing performance of: regex start vs startsWith vs regex end vs endsWith vs indexOf start vs indexOf end

Created: 5 years ago by: Registered User

Jump to the latest result

regex start

startsWith

regex end

endsWith

indexOf start

indexOf end

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):