Benchmark: Delete vs destructure vs reduce for objects

Script Preparation code:

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

Tests:

delete
delete obj.a
Rest object
const { a, ...rest } = obj;
Reduce
const obj2 = Object.keys(obj).reduce((acc, cur) => { if (cur !== 'a') { acc[cur] = obj[cur] } return acc },{})

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
delete
Rest object
Reduce

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark tests three different approaches to delete or remove properties from an object: `delete`, `destructuring assignment` (using `const { a, ...rest } = obj;`), and `reduce()` method. We'll explore each approach, its pros and cons, and other considerations.

**1. `delete` approach**

This approach uses the built-in `delete` operator to delete properties from an object.

Pros:

* Simple and concise syntax.
* Fast and efficient execution.

Cons:

* Can be slower than destructuring assignment or reduce() method for large objects due to the way JavaScript handles property deletion.
* May not work as expected in certain situations, such as when working with `const` variables or in older browsers.

Other considerations:

* The `delete` operator works by creating a new property with the same name as the one being deleted, but with an undefined value. This can lead to unexpected behavior if the resulting object is used in further computations.
* In modern JavaScript engines, `delete` is generally faster than using the `in` operator to check for the existence of a property.

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

This approach uses destructuring assignment to remove properties from an object by extracting them into separate variables.

Pros:

* Fast and efficient execution.
* Can be more readable and concise than using `delete`.
* Works well with `const` variables and in modern browsers.

Cons:

* May not work as expected if the property being deleted is a function or has other complex properties.
* Requires knowledge of destructuring assignment syntax, which can be unfamiliar to some developers.

Other considerations:

* Destructuring assignment creates new variables for each extracted property. This can lead to more memory usage and slower performance compared to using `delete`.
* The resulting object will have the same properties as the original object, but with the removed property set to `undefined`.

**3. `reduce()` method approach**

This approach uses the `reduce()` method to create a new object with only the desired properties.

Pros:

* Fast and efficient execution.
* Works well with large objects and can be more memory-efficient than destructuring assignment.
* Can be more readable and concise for complex property removal scenarios.

Cons:

* Requires knowledge of the `reduce()` method syntax, which can be unfamiliar to some developers.
* May not work as expected if the property being deleted is a function or has other complex properties.

Other considerations:

* The `reduce()` method creates a new object using a callback function. This can lead to slower performance compared to using `delete` directly on an object.
* The resulting object will have only the desired properties, but may not be as intuitive to read and understand as the original object.

In summary, each approach has its strengths and weaknesses. The choice of approach depends on the specific use case, personal preference, and familiarity with JavaScript features.

As for other alternatives, there are a few more approaches that can be used to delete or remove properties from an object:

* `Object.keys()`, `Array.prototype.filter()`, and `Array.prototype.map()` can be used together to achieve similar results as the `reduce()` method approach.
* Using `Object.assign()` with an empty object to create a new object with only the desired properties.
* Utilizing the `Symbol` property to define private variables and use destructuring assignment or `delete` accordingly.

Keep in mind that each of these alternatives has its own trade-offs, pros, and cons.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:106.0) Gecko/20100101 Firefox/106.0

Browser/OS: Firefox 106 on Windows

View result in a separate tab

Test name	Executions per second
delete	24582048.0 Ops/sec
Rest object	6054964.0 Ops/sec
Reduce	4881365.5 Ops/sec

Related benchmarks:

Delete vs destructure vs reduce for objects (version: 0)

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

Comparing performance of: delete vs Rest object vs Reduce

Created: 3 years ago by: Guest

Jump to the latest result

delete

Rest object

Reduce

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):