Benchmark: Long String equality comparison

Script Preparation code:

function createRandomString(length) {
  for (var i=0; i<length; i++) {
	  longString += Math.random() < 0.1 ? ' ' : String.fromCharCode(65+Math.floor(Math.random() * 30));
  }
}
var longString = createRandomString(600000);
var totallyDifferentLongString = createRandomString(600000);
var endDiffLongString = longString + ' different';
var startDiffLongString = 'different ' + longString;
var sameLongString = '' + longString;

var shortString = createRandomString(100);
var totallyDifferentShortString = createRandomString(100);

var RUNS = 10000;

Tests:

Long Equality
for (var i=0; i<RUNS; i++) longString === sameLongString
Start Long Difference
for (var i=0; i<RUNS; i++) longString === startDiffLongString
End Long Difference
for (var i=0; i<RUNS; i++) longString === endDiffLongString
Totally Long Difference
for (var i=0; i<RUNS; i++) longString === totallyDifferentLongString
Totally Short Difference
for (var i=0; i<RUNS; i++) shortString === totallyDifferentShortString

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Long Equality
Start Long Difference
End Long Difference
Totally Long Difference
Totally Short Difference

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 dive into the provided benchmark and explore what is being tested, compared options, pros and cons, library usage, special JavaScript features or syntax, and alternative approaches.

**What is being tested?**

The test cases are designed to measure the performance of JavaScript equality comparison operators on long strings. There are four test cases:

1. `Long Equality`: Compare a long string (`longString`) with itself.
2. `Start Long Difference`: Compare a long string (`longString`) with a string that has one character removed from the beginning.
3. `End Long Difference`: Compare a long string (`longString`) with a string that has one character added to the end.
4. `Totally Long Difference`: Compare a long string (`longString`) with a completely different string.

**Comparison options**

There are two primary comparison operators being tested:

1. `===` (strict equality): Tests whether the values of both variables are equal, including data types and values.
2. `==` (loose equality): Tests whether the values of both variables are equal, but ignores data types.

The test results provide execution counts per second for each comparison operator on different devices.

**Pros and cons**

1. **`===` (strict equality)**:
	* Pros: Ensures strict equivalence between values, including data types.
	* Cons: May lead to slower performance due to type checking.
2. **`==` (loose equality)**:
	* Pros: Faster performance since it ignores data types.
	* Cons: May lead to incorrect results if values are not equivalent despite being of the same data type.

**Library usage**

There is no explicit library mentioned in the provided code. However, the use of `String.fromCharCode(65+Math.floor(Math.random() * 30))` suggests that a random character might be generated for each iteration of the loop, which is often used to generate unique strings or test string processing performance.

**Special JavaScript features or syntax**

There are no special JavaScript features or syntax being tested in this benchmark. The focus is on comparing long strings using basic equality operators.

**Alternative approaches**

If you wanted to test alternative comparison approaches, such as:

1. **Regular expressions**: Instead of using `===` or `==`, regular expressions could be used to compare the contents of the strings.
2. **JSON-based comparisons**: The benchmark could use JSON objects to represent the long strings and compare them using `JSON.stringify()` and `JSON.parse()`.
3. **Hash-based comparisons**: Similar to regular expressions, hash tables (like JavaScript's `Map`) could be used to store and compare the contents of the strings.

However, these approaches might require modifications to the existing benchmark code and may not provide comparable results.

Keep in mind that this is a simple benchmark focusing on string equality comparison. Depending on your specific use case or requirements, you might need to create more complex benchmarks testing other aspects of JavaScript performance.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.99 Safari/537.36

Browser/OS: Chrome 97 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Long Equality	466.1 Ops/sec
Start Long Difference	470.2 Ops/sec
End Long Difference	468.8 Ops/sec
Totally Long Difference	476.0 Ops/sec
Totally Short Difference	467.8 Ops/sec

Related benchmarks:

Long String equality comparison (version: 2)

Comparing performance of: Long Equality vs Start Long Difference vs End Long Difference vs Totally Long Difference vs Totally Short Difference

Created: 4 years ago by: Registered User

Jump to the latest result

Long Equality

Start Long Difference

End Long Difference

Totally Long Difference

Totally Short Difference

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):