Benchmark: Delete vs destructure for objects

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: 5 days ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.2 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.2

View result in a separate tab

Test name	Executions per second
delete	628596224.0 Ops/sec
Rest object	29356544.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark is designed to measure the performance of two different approaches:

1. **Delete**: This approach uses the `delete` operator to remove a property from an object.
2. **Rest Object**: This approach uses destructuring assignment ( introduced in ECMAScript 2015) to extract a subset of properties from an object.

**Options being compared**

The benchmark compares two options for removing or extracting properties from an object:

1. `delete` operator
2. Destructuring assignment ( `const { a, ...rest } = obj;` )

**Pros and Cons**

### Delete Operator

Pros:

* Simple and straightforward syntax
* Widely supported in most browsers and JavaScript engines
* Can be used with any type of object, not just objects

Cons:

* May involve more overhead due to the creation of a new variable ( `obj.a` )
* Can lead to unexpected behavior if not used carefully (e.g., modifying the original object)

### Destructuring Assignment

Pros:

* More concise and expressive syntax
* Only creates a copy of the subset of properties, which can be beneficial for large objects
* Less likely to modify the original object unintentionally

Cons:

* Introduced in ECMAScript 2015, so may not be supported in older browsers or engines
* Requires knowledge of destructuring assignment syntax

**Library and Special JS Feature**

There is no explicit library mentioned in the benchmark definition. However, it's worth noting that the use of `const { a, ...rest } = obj;` demonstrates the use of destructuring assignment, which is a standard JavaScript feature.

**Other Alternatives**

If you're interested in exploring other alternatives for removing or extracting properties from an object, here are a few options:

* Using a function to dynamically remove properties (e.g., `function removeProperty(obj, key) { delete obj[key]; }`)
* Using a library like Lodash's `remove` function
* Using a custom implementation of object removal, such as using a hash table to store property names and values

Keep in mind that these alternatives may have different performance characteristics or trade-offs compared to the `delete` operator and destructuring assignment.

Related benchmarks:

Delete vs destructure for objects (version: 0)

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

Comparing performance of: delete vs Rest object

Created: 5 years ago by: Guest

Jump to the latest result

delete

Rest object

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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