Benchmark: Access first key using for-in vs object.keys() 2

Script Preparation code:

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function testForIn () {
	for (const key in object)
      return key;
}

function testObjectKeys() {
  return Object.keys(object)[0];
}

Tests:

for in
testForIn();
object keys
testObjectKeys();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for in
object keys

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Based on the provided benchmark data, I can infer some information about the performance of these two test cases.

**For `in` loop**

* The average execution time per second is approximately 18,768,434 (18768434.0).
* This suggests that the `in` loop is relatively slow compared to other JavaScript operations.
* To improve this, consider using more efficient data structures and algorithms for iterating over objects.

**Using `Object.keys()`**

* The average execution time per second is approximately 5,398,815 (5398815.0).
* This suggests that the `Object.keys()` method is relatively fast compared to other JavaScript operations.
* However, it may be worth noting that this method involves creating an array of keys, which can be a memory-intensive operation.

**Recommendations**

1. **Use more efficient data structures**: For large objects, consider using Array.prototype.forEach() or Map.prototype.forEach(), which are generally faster and more efficient than iterating over the `in` operator.
2. **Optimize object iteration**: If you must use an `in` loop for some reason, make sure to clear the cache or use a mechanism like requestAnimationFrame() to minimize overhead.
3. **Consider using `Object.entries()` or `Object.values()`**: These methods may be faster and more efficient than iterating over the `in` operator, depending on your specific use case.

Keep in mind that these are general suggestions based on the provided benchmark data. The actual performance impact will depend on your specific codebase, requirements, and hardware configuration.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36

Browser/OS: Chrome 118 on Windows

View result in a separate tab

Test name	Executions per second
for in	18768434.0 Ops/sec
object keys	5398815.0 Ops/sec

Related benchmarks:

Access first key using for-in vs object.keys() 2 (version: 0)

Comparing performance of: for in vs object keys

Created: one year ago by: Guest

Jump to the latest result

for in

object keys

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):