Benchmark: Test 03 - MeasureThat.net

Tests:

One
const obj = { key1: 'value1', key2: 'value2' }; if ('key1' in obj) { console.log('key1 exists in obj'); } else { console.log('key1 does not exist in obj'); }
Two
const obj = { key1: 'value1', key2: 'value2' }; if (obj.hasOwnProperty('key1')) { console.log('key1 exists in obj'); } else { console.log('key1 does not exist in obj'); }
Three
const obj = { key1: 'value1', key2: 'value2' }; if (typeof obj.key1 !== 'undefined') { console.log('key1 exists in obj'); } else { console.log('key1 does not exist in obj'); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
One
Two
Three

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

I'll explain what's being tested in the provided JSON.

**Benchmark Definition**

The benchmark definition is not explicitly stated, but based on the test cases, it appears that the benchmark is testing the performance of different approaches to check if a key exists in an object. The script preparation code is empty, and the HTML preparation code is also empty, which suggests that the benchmark is focusing solely on the JavaScript execution.

**Test Cases**

There are three test cases:

1. **Case One**: This case uses the `in` operator to check if the key exists in the object.
```javascript
if ('key1' in obj) {
  console.log('key1 exists in obj');
} else {
  console.log('key1 does not exist in obj');
}
```
2. **Case Two**: This case uses the `hasOwnProperty` method to check if the key exists in the object.
```javascript
if (obj.hasOwnProperty('key1')) {
  console.log('key1 exists in obj');
} else {
  console.log('key1 does not exist in obj');
}
```
3. **Case Three**: This case uses the `typeof` operator with a nullish coalescing (`??`) to check if the key exists in the object.
```javascript
if (typeof obj.key1 !== 'undefined') {
  console.log('key1 exists in obj');
} else {
  console.log('key1 does not exist in obj');
}
```
**Comparison**

The three test cases are comparing the performance of different approaches to check if a key exists in an object. Here's a brief pros and cons analysis:

* **Case One**: `in` operator is generally faster than `hasOwnProperty` because it checks if the key is present in the object's prototype chain as well.
	+ Pros: Simple, fast, widely supported.
	+ Cons: May return false positives (i.e., if the property exists in a prototype), may be slower for large objects due to additional checks.
* **Case Two**: `hasOwnProperty` method is specifically designed to check if a key exists in an object's own properties, avoiding potential issues with prototypes.
	+ Pros: More accurate than `in` operator, avoids potential false positives.
	+ Cons: May be slightly slower than `in` operator due to additional checks.
* **Case Three**: Nullish coalescing (`??`) is a relatively new feature in JavaScript that allows for faster comparisons with null or undefined values. In this case, it may provide better performance than the other two approaches.
	+ Pros: Fast, simple, and modern approach.
	+ Cons: May not be supported by older browsers or versions of JavaScript.

**Library**

In none of the test cases is a library explicitly used. However, if we were to extend these tests to include libraries, we might consider using the following:

* Lodash's `_.has()` function for `hasOwnProperty`-style checks.
* A modern JavaScript runtime (e.g., V8) for optimized execution.

**Special JS Features**

Case Three uses nullish coalescing (`??`), which is a relatively new feature in JavaScript. If you're targeting older browsers or versions of JavaScript, this approach may not be supported.

**Alternatives**

If you wanted to test alternative approaches to checking if a key exists in an object, you might consider the following:

* Using `Object.prototype.hasOwnProperty.call()` instead of `hasOwnProperty`.
* Using a library like Lodash's `_.has()` function.
* Using a custom implementation with a simple loop or recursive approach.

Keep in mind that these alternatives may have different performance characteristics or trade-offs compared to the original test cases.

Related benchmarks:

Test 03 (version: 0)

Comparing performance of: One vs Two vs Three

Created: 3 years ago by: Guest

Jump to the latest result

One

Two

Three

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):