Benchmark: Comare ^Regex vs startsWith, .search vs .indexOf, .test vs .include (spelled correctly)

HTML Preparation code:

<div></div>

Script Preparation code:

window.matchStartRegex = /^test/;
window.matchRegex = /test/;
window.matchSubstr = 'test';
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:

^test Regex
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var regex = window.matchStartRegex; let result = false; while (x < TOTAL_STRINGS) { const str = data[x]; result = regex.test(str); x += 1; }
.startsWith
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.matchSubstr; let result = false; while (x < TOTAL_STRINGS) { const str = data[x]; result = str.startsWith(match); x += 1; }
.search(RegExp)
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var regex = window.matchRegex; let result = false; while (x < TOTAL_STRINGS) { const str = data[x]; result = str.search(regex); x += 1; }
.indexOf
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.matchSubstr; let result = -1; while (x < TOTAL_STRINGS) { const str = data[x]; result = str.indexOf(match); x += 1; }
RegExp # test
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var regex = window.matchRegex; let result = false; while (x < TOTAL_STRINGS) { const str = data[x]; result = regex.test(str); x += 1; }
.includes
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.matchSubstr; let result = false; while (x < TOTAL_STRINGS) { const str = data[x]; result = str.includes(match); x += 1; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
^test Regex
.startsWith
.search(RegExp)
.indexOf
RegExp # test
.includes

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.54 Safari/537.36

Browser/OS: Chrome 95 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
^test Regex	418.4 Ops/sec
.startsWith	500.2 Ops/sec
.search(RegExp)	257.6 Ops/sec
.indexOf	7239.9 Ops/sec
RegExp # test	295.9 Ops/sec
.includes	319.9 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, the pros and cons of each approach, and other considerations.

**Benchmark Overview**

The benchmark tests four different string matching methods in JavaScript:

1. `^test Regex` (starts with)
2. `.startsWith`
3. `.search(RegExp)`
4. `.indexOf`

These methods are compared to measure their performance differences.

**Options Compared**

Here's a brief explanation of each method and its purpose:

1. **^test Regex**: This is a custom implementation that matches strings starting with the literal text "test". It uses a regular expression (regex) with the caret `^` symbol, which anchors the match to the beginning of the string.
2. **.startsWith**: This is a built-in JavaScript method that checks if a string starts with another string. It returns `true` if the original string begins with the specified string, or `false` otherwise.
3. **.search(RegExp)**: This is a built-in JavaScript method that searches for a regex pattern within a string and returns the index of the match. If no match is found, it returns `-1`.
4. **.indexOf**: This is another built-in JavaScript method that finds the index of a specified value in a string. It's similar to `.search`, but returns the index of the first occurrence of the value instead of the matched pattern.

**Pros and Cons**

Here are some pros and cons for each approach:

1. **^test Regex**:
	* Pros: Customizable, exact match (starts with "test").
	* Cons: May be slower due to regex processing.
2. **.startsWith**:
	* Pros: Built-in method, simple implementation.
	* Cons: May not work correctly for non-string values or edge cases.
3. **.search(RegExp)**:
	* Pros: Flexible regex patterns, efficient matching.
	* Cons: Requires explicit regex pattern creation and handling errors.
4. **.indexOf**:
	* Pros: Simple, fast indexing.
	* Cons: Returns index of first occurrence, not exact match.

**Other Considerations**

* The benchmark uses a custom implementation for `^test Regex`, which may affect the results. Standardized implementations might yield different performance characteristics.
* The use of built-in methods like `.startsWith` and `.indexOf` can provide good performance, as they are optimized for these specific use cases.
* The custom regex pattern in `^test Regex` is a simple string match, whereas `.search(RegExp)` allows more complex patterns. This difference may impact performance.

**Benchmark Results**

The latest benchmark results show the performance differences between each method. Chrome 95 on Mac OS X 10.15.7 executes:

* `.indexOf`: ~295ms per second
* `.startsWith`: ~257ms per second
* `^test Regex`: ~319ms per second (custom implementation)
* `.search(RegExp)`: ~257ms per second

Keep in mind that these results may vary depending on the specific use case, input data, and environment.

Related benchmarks:

Comare ^Regex vs startsWith, .search vs .indexOf, .test vs .include (spelled correctly) (version: 0)

Testing some things

Comparing performance of: ^test Regex vs .startsWith vs .search(RegExp) vs .indexOf vs RegExp # test vs .includes

Created: 3 years ago by: Guest

Jump to the latest result

^test Regex

.startsWith

.search(RegExp)

.indexOf

RegExp # test

.includes

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):