Benchmark: Array comparison

Script Preparation code:

var x = [];
var y = [];
for (var i = 0; i < 100000; i++) {
  x[i] = {};
  y[i] = x[i];
}

Tests:

Array comparison
var isEqual = true; for (var i = 0, len = x.length; i < len; i++) { if (x[i] !== y[i]) { isEqual = false; break; } }
Simple comparison
x === y;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array comparison
Simple comparison

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array comparison	4459.2 Ops/sec
Simple comparison	162919152.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its options.

**What is being tested?**

The provided JSON represents two benchmark tests: "Array Comparison" and "Simple Comparison". Both benchmarks compare two arrays of length 100,000.

**Options compared**

There are two approaches to compare the two arrays:

1. **Manual loop comparison**: In this approach, a manual loop iterates through each element of both arrays and checks if they are equal using the `!==` operator. If any mismatch is found, the `isEqual` variable is set to `false`.
2. **Direct array equality check**: In this approach, the two arrays are compared directly using the `===` operator.

**Pros and Cons**

* Manual loop comparison:
	+ Pros: This approach can be more intuitive for developers familiar with loops, as it allows them to control the iteration process.
	+ Cons: It's generally slower than direct array equality checks due to the overhead of manually looping through each element.
* Direct array equality check:
	+ Pros: This approach is usually faster and more efficient, as it leverages the optimized internal logic of JavaScript engines for comparing arrays.
	+ Cons: It can be less intuitive for developers not familiar with this syntax.

**Library and its purpose**

There is no explicit library mentioned in the benchmark. However, since both benchmarks involve array comparisons, the built-in JavaScript `Array.prototype.every()` or `Array.prototype.everyIndex()` methods could be used to simplify these comparisons. These methods would return a boolean value indicating whether all elements in the array satisfy the provided callback function.

**Special JS feature or syntax**

The benchmark does not explicitly use any special JavaScript features or syntax that are not part of the standard language.

**Other alternatives**

For more efficient and modern array comparison approaches, consider using:

1. `Array.prototype.every()` or `Array.prototype.everyIndex()`: These methods provide a concise way to check if all elements in an array meet a condition.
2. `Array.prototype.equals()`: This method is available in some JavaScript engines (e.g., V8) and provides a direct equality comparison for arrays.

These alternatives can potentially outperform the manual loop or direct equality check approaches, but their usage may require additional setup or dependencies.

In conclusion, the benchmark tests two common approaches to comparing arrays: a manual loop comparison using the `!==` operator and a direct array equality check using the `===` operator. While the manual loop approach has its advantages, the direct equality check is generally faster and more efficient.

Related benchmarks:

Array comparison (version: 0)

Compare two arrays of length 100,000

Comparing performance of: Array comparison vs Simple comparison

Created: 8 years ago by: Guest

Jump to the latest result

Array comparison

Simple comparison

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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