Benchmark: Delete vs destructure for objects v2 2

Script Preparation code:

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

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
delete
Rest object

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/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
delete	79213232.0 Ops/sec
Rest object	2906867.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its components.

**Benchmark Definition**

The benchmark is defined by a JSON object that contains information about the test case:

* `Name`: The name of the benchmark, which in this case is "Delete vs destructure for objects v2 2".
* `Description`: A brief description of what the benchmark measures.
* `Script Preparation Code` and `Html Preparation Code`: These are codes that are executed before running the benchmark. In this case, only the script preparation code is provided.

**Script Preparation Code**

The script preparation code is a JavaScript snippet that creates an object with three properties: `a`, `b`, and `c`. The object is assigned to a variable named `obj`.

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

**Individual Test Cases**

The benchmark consists of two individual test cases:

* **delete**: This test case measures the performance of using the `delete` keyword to remove a property from an object. The benchmark definition is: `delete obj.a`.
* **Rest object**: This test case measures the performance of creating a rest object using destructuring assignment. The benchmark definition is: `const { a, ...rest } = obj;`.

**Options Compared**

The two test cases compare different approaches to removing properties from an object.

1. **Delete**: Using the `delete` keyword.
2. **Destructure**: Creating a rest object using destructuring assignment (`{ a, ...rest } = obj`).

**Pros and Cons of Each Approach**

* **Delete**:
	+ Pros: Simple and straightforward syntax.
	+ Cons: Can be slower due to the overhead of removing a property from an object.
* **Destructure**:
	+ Pros: More concise syntax and potentially faster performance since it avoids modifying the original object.
	+ Cons: Requires JavaScript 2015+ syntax, which not all browsers support.

**Library Used (if any)**

None.

**Special JS Feature or Syntax**

The `Rest object` test case uses a feature introduced in ECMAScript 2015 (ES6) called destructuring assignment. This feature allows you to create new objects by extracting properties from an existing object.

```javascript
const { a, ...rest } = obj;
```

In this example, the expression `{ a, ...rest } = obj` creates a new object `rest` that includes all properties of `obj`, except for `a`.

**Other Alternatives**

While not exactly equivalent, other ways to remove properties from an object could be:

* Using `Object.prototype.hasOwnProperty.call(obj, 'a') && delete obj['a']`
* Creating a new object with the desired properties and then assigning it to a variable
* Using `Array.prototype.slice.call(Object.keys(obj).map(key => ({ [key]: obj[key] }))`

However, these alternatives are not as concise or efficient as using the `delete` keyword or destructuring assignment.

Related benchmarks:

Delete vs destructure for objects v2 2 (version: 0)

Measure the performance of delete versus removing a prop from an object

Comparing performance of: delete vs Rest object

Created: 3 years ago by: Guest

Jump to the latest result

delete

Rest object

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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