Benchmark: Substr vs startsWith GUL

HTML Preparation code:

<div></div>

Script Preparation code:

window.test = '$meta-';
window.testLen = window.test.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 = "";
  if (getRandomInt(2) === 1) {
    text += window.test;
  }
  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:

startsWith
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var test = window.test; while (x < TOTAL_STRINGS) { const str = data[x]; str.startsWith(test); x += 1; }
substr
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var test = window.test; var testLen = window.testLen; while (x < TOTAL_STRINGS) { const str = data[x]; str.length >= testLen && str.substr(0, testLen) === test; x += 1; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith
substr

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its components.

**Benchmark Definition JSON**

The provided `Benchmark Definition` JSON represents two test cases: `substr` and `startsWith`. The main difference between these two tests is how they compare strings:

1. **Substring Comparison (substr)**:
	* In this test, a random string `str` is generated from the dataset.
	* The length of `str` is compared to the length of the predefined substring `test`.
	* If the lengths match and the first `testLen` characters of `str` are equal to `test`, the comparison is considered successful.
2. **Substring Comparison with Start (startsWith)**:
	* Similar to the previous test, a random string `str` is generated from the dataset.
	* The test checks if the substring starting from the beginning of `str` and having the same length as `test` matches `test`.

**Comparison Options**

There are two comparison options being tested:

1. **Substring Comparison (substr)**: This approach compares a portion of one string (`str`) with another fixed-length substring (`test`).
2. **Substring Comparison with Start (startsWith)**: In this approach, the test checks if the start of a randomly generated string matches a predefined substring.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **Substring Comparison (substr)**
	* Pros:
		+ More flexible, as it allows for different types of comparisons (e.g., prefix, suffix).
		+ Can be optimized for performance.
	* Cons:
		+ May require more memory to store the intermediate results of substring extraction.
2. **Substring Comparison with Start (startsWith)**
	* Pros:
		+ More predictable and consistent behavior.
		+ Reduces the number of potential collisions between substrings.
	* Cons:
		+ Less flexible than the `substr` approach.

**Library**

There is no explicit library mentioned in the benchmark definition, but it's likely that the built-in JavaScript `String.prototype.startsWith()` method is being used in both test cases.

**Special JS Features/Syntax**

None of the provided benchmarks use special JavaScript features or syntax. The focus appears to be on the comparison logic and performance optimization.

**Other Alternatives**

Some alternative approaches for comparing strings could include:

1. **Regular Expressions**: Instead of using substrings, regular expressions can provide more flexibility and power for string matching.
2. **Hash Tables**: Storing the strings in a hash table and then performing lookups could potentially improve performance, especially for large datasets.
3. **Approximate String Matching**: If exact matches are not required, algorithms like Levenshtein distance or Jaro-Winkler distance can provide more efficient string comparison.

Keep in mind that these alternative approaches may have their own trade-offs and require additional resources (e.g., memory, computational power).

Related benchmarks:

Substr vs startsWith GUL (version: 0)

Benchmarking usage of comparaison of substr result and starts with

Comparing performance of: startsWith vs substr

Created: 5 years ago by: Guest

Jump to the latest result

startsWith

substr

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):