Benchmark: Testing the benchmark for delete

Script Preparation code:

var obj = {
  a:1,
  b:2,
  c:3,
  d: 4,
  e: 5, 
  f: 6,
  g: 7
}

Tests:

xxx
const copy = Object.assign({}, obj); delete obj.a; delete obj.b delete obj.c delete obj.d delete obj.e
yyy
const { a, b, c, d, e, ...rest } = obj;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
xxx
yyy

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/109.0.0.0 Safari/537.36

Browser/OS: Chrome 109 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
xxx	1591494.1 Ops/sec
yyy	2204806.2 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated one month ago):

LLMs can make mistakes. Check important info.

This benchmark compares two ways to remove properties from a JavaScript object:

**Option 1:**  Deleting properties one by one using the `delete` operator.

```javascript
const copy = Object.assign({}, obj); // Create a copy of the original object
delete obj.a;
delete obj.b
delete obj.c
delete obj.d
delete obj.e
```

**Option 2:** Using destructuring assignment to extract specific properties and leave the rest in a new object.

```javascript
const { a, b, c, d, e, ...rest } = obj; // Extract a, b, c, d, e  into individual variables and put the remaining properties into 'rest' 
```

**Pros and Cons:**

* **Option 1 (delete):**
    * **Pro:** Simple and straightforward to understand.
    * **Con:** Can be slow for large objects as each deletion involves potentially traversing property chains.  This approach modifies the original object directly.
* **Option 2 (destructuring):**
    * **Pro:** More concise and readable, especially when dealing with a large number of properties. Potentially more efficient as it avoids repeated modifications to the original object. This approach creates a new object without modifying the original.

**Other Considerations:**

* **Object Size:** For very small objects, the performance difference between these options might be negligible. However, for larger objects, the efficiency gains of destructuring become more apparent.
* **Readability and Maintainability:** Destructuring assignment can often lead to cleaner and more readable code, making it easier to understand and maintain.

**Alternatives:**

* **`JSON.parse(JSON.stringify(obj))`:** This creates a deep copy of the object, effectively removing all references to the original. You can then delete properties from the new copy. 
* **Iterating over keys:**  You could use `for...in` or `Object.keys()` to iterate over the object's properties and manually delete them.

Let me know if you have any other questions!

Related benchmarks:

Testing the benchmark for delete (version: 0)

var obj = { a:1, b:2, c:3, d: 4, e: 5, f: 6, g: 7 }

Comparing performance of: xxx vs yyy

Created: one year ago by: Guest

Jump to the latest result

xxx

yyy

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated one month ago):