Benchmark: Compare delete vs rest destructuring

Script Preparation code:

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

Tests:

delete
delete obj.a; delete obj.b; delete obj.c;
Rest obj
const { a, b, c, ...rest } = obj;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
delete
Rest obj

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.

Let's dive into the world of JavaScript microbenchmarks.

**What is tested?**

The provided JSON represents two individual test cases: "delete" and "Rest obj". These test cases are designed to compare the performance of two different approaches:

1. **Delete**: The `delete` keyword is used to delete properties from an object.
2. **Rest obj**: Object destructuring using the rest syntax (`const { a, b, c, ...rest } = obj;`) is used to extract multiple values from an object and discard the remaining ones.

**Options compared**

The two test cases compare the performance of these two approaches:

* `delete` keyword
* Object destructuring with rest syntax

**Pros and Cons of each approach:**

1. **Delete keyword**:
	* Pros:
		+ Simple and widely supported.
		+ Works in older browsers.
	* Cons:
		+ Can be slower than object destructuring due to the need for a garbage collection cycle.
		+ May cause issues with some libraries or frameworks that rely on the `delete` keyword's behavior.
2. **Object destructuring with rest syntax**:
	* Pros:
		+ Faster and more efficient, as it avoids the need for a garbage collection cycle.
		+ More modern and widely supported (introduced in ECMAScript 2015).
	* Cons:
		+ May not work in older browsers that don't support it.
		+ Can be less readable or less familiar to some developers.

**Library and purpose**

There are no specific libraries mentioned in the provided code. However, object destructuring is a built-in JavaScript feature introduced in ECMAScript 2015.

**Special JS feature or syntax**

Object destructuring with rest syntax (`const { a, b, c, ...rest } = obj;`) is a modern JavaScript feature that allows you to extract multiple values from an object and discard the remaining ones. This approach is faster and more efficient than using the `delete` keyword.

**Other alternatives**

If you're looking for alternative approaches, here are a few:

1. **Object.keys() and array methods**: You can use `Object.keys()` to get an array of property names and then filter or map them to achieve similar results.
2. **For...in loop**: You can use a `for...in` loop to iterate over the object's properties and manually delete each one.

Here's an example using `Object.keys()`:
```javascript
const obj = { a: 1, b: 2, c: 3 };
const restObj = {};
Object.keys(obj).forEach(key => {
  if (key !== 'a' && key !== 'b') {
    restObj[key] = obj[key];
  }
});
```
Keep in mind that this approach may not be as efficient or readable as object destructuring with rest syntax.

Related benchmarks:

Compare delete vs rest destructuring (version: 0)

Comparing performance of: delete vs Rest obj

Created: 4 years ago by: Registered User

Jump to the latest result

delete

Rest obj

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):