Benchmark: delete vs destructure javascript performance

Script Preparation code:

var obj = {
  a:1,
  b:2,
  c:3
}

Tests:

delete
delete obj.a return obj
spread
const { a, ...rest } = obj return rest

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
delete
spread

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.2 Safari/605.1.15

Browser/OS: Safari 26 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
delete	568811136.0 Ops/sec
spread	32021072.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided JSON and explain what's being tested, the options compared, pros and cons of each approach, and other considerations.

**Benchmark Definition**

The benchmark measures the performance difference between two approaches: deleting an object property using the `delete` keyword versus destructuring an object using the spread operator (`...`). The script preparation code creates a simple object with three properties (`a`, `b`, and `c`) and assigns it to a variable named `obj`.

**Script Preparation Code**

```javascript
var obj = {
  a: 1,
  b: 2,
  c: 3
}
```

This creates an object with initial values for each property.

**Individual Test Cases**

There are two test cases:

1. **`delete`**: This test case uses the `delete` keyword to delete the `a` property from the `obj` object and returns the updated object.
```javascript
delete obj.a
return obj
```

2. **`spread`**: This test case uses the spread operator (`...`) to create a new object that includes all properties of the original object, except for the deleted `a` property. The resulting object is then returned.
```javascript
const { a, ...rest } = obj
return rest
```

**Comparison**

The two approaches are compared in terms of performance. The benchmark aims to measure which approach is faster.

**Pros and Cons:**

1. **`delete`**:
	* Pros:
		+ Simple and straightforward syntax.
	* Cons:
		+ May not be as efficient as other methods, as it requires a separate memory allocation for the deleted property.
2. **`spread`**:
	* Pros:
		+ More efficient than `delete`, as it reuses the existing object's memory allocation.
	* Cons:
		+ Requires a more complex syntax and understanding of the spread operator.

**Other Considerations**

*   The benchmark does not account for any potential side effects or changes to the original object after deletion or destruction. These effects might impact performance, but they are not considered in this test case.
*   It's worth noting that JavaScript engines may optimize some operations under the hood, which could affect the observed results.

**Alternative Approaches**

Other approaches that could be used for similar tasks include:

*   Using `Object.prototype.hasOwnProperty.call(obj, 'a')` to check if a property exists before deleting it.
*   Implementing a custom solution using bitwise operations or other low-level techniques to delete properties more efficiently.
*   Utilizing modern JavaScript features like `Object.entries()` and `Array.from()` for destructuring.

Keep in mind that the performance differences between these approaches may be small, and the choice of method often depends on readability, maintainability, and personal preference.

Related benchmarks:

delete vs destructure javascript performance (version: 0)

Comparing performance of: delete vs spread

Created: one year ago by: Guest

Jump to the latest result

delete

spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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