Benchmark: object isEmpty test2

Script Preparation code:

var obj1 = {
  foo: 'bar'
};
var obj0 = {};

function isEmpty1(obj) {
  return !!obj && Object.keys(obj).length === 0 && obj.constructor === Object;
}

function isEmpty2(obj) {
  if (!obj || obj.constructor !== Object) {
    return false;
  }

  for (var key in obj) {
    if (Object.prototype.hasOwnProperty.call(obj, key)) {
      return false;
    }
  }

  return true;
}

Tests:

isEmpty1
var result1 = []; for (let i = 0; i < 100; i += 1) { result1[i] = i % 2 ? isEmpty1(obj1) : isEmpty1(obj0); }
isEmpty2
var result2 = []; for (let i = 0; i < 100; i += 1) { result2[i] = i % 2 ? isEmpty2(obj1) : isEmpty2(obj0); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
isEmpty1
isEmpty2

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition, test cases, and latest benchmark result to explain what's being tested.

**Benchmark Definition**

The benchmark measures the performance of two different approaches for checking if an object is empty:

1. `isEmpty1(obj)`: This function returns `true` if the object has no keys (i.e., it's an empty object), and its constructor is also `Object`. The purpose of this check is to ensure that we're not comparing the object with `null` or any other non-object value.
2. `isEmpty2(obj)`: This function uses a for...in loop to iterate over the object's keys. If any key exists, it returns `false`, indicating that the object is not empty.

**Options Compared**

The two approaches are compared in terms of performance, specifically:

* Which approach is faster?
* Does one approach have better cache locality than the other?

**Pros and Cons**

1. **`isEmpty1(obj)`**:
	* Pros: Simple and efficient, as it only checks if the object has no keys.
	* Cons: It may not cover all cases (e.g., comparing with `null`), which might lead to false positives or negatives.
2. **`isEmpty2(obj)`**:
	* Pros: More comprehensive, as it checks for existing keys in addition to checking the constructor.
	* Cons: The for...in loop may introduce more overhead due to iteration and potential caching issues.

**Library**

None of the test cases use any external libraries or frameworks.

**Special JS Feature or Syntax**

There's no explicit mention of special JavaScript features or syntax being used. However, it's worth noting that the `for...in` loop in `isEmpty2(obj)` uses a legacy syntax (prior to ECMAScript 2015).

**Other Considerations**

When interpreting benchmark results, keep in mind:

* The benchmark only measures performance for specific use cases (checking if an object is empty).
* Other factors like memory allocation, garbage collection, or branch prediction might influence the actual performance difference between the two approaches.

**Alternatives**

If you want to explore alternative approaches, consider these options:

1. Using `Object.keys(obj).length === 0` instead of checking the constructor (as in `isEmpty1(obj)`).
2. Utilizing modern JavaScript features like `Array.prototype.every()` or `Array.prototype.filter()` to check if all keys exist.
3. Implementing a custom hash function or using a library like Lodash to optimize object emptiness checks.

Keep in mind that the best approach depends on the specific use case and performance requirements of your application.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36

Browser/OS: Chrome 96 on Windows

View result in a separate tab

Test name	Executions per second
isEmpty1	29526.9 Ops/sec
isEmpty2	29051.8 Ops/sec

Related benchmarks:

object isEmpty test2 (version: 2)

Comparing performance of: isEmpty1 vs isEmpty2

Created: 3 years ago by: Registered User

Jump to the latest result

isEmpty1

isEmpty2

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):