Benchmark: delete property of object vs create new object

Script Preparation code:

var obj = {}
for (let i = 0; i < 1000; i++) {
	obj[`test_${i}`] = `value_${i}`;
}

Tests:

create new object
const newObject = Object.keys(obj).reduce((object, key) => { if (key) { object[key] = obj[key] } return object }, {})
directly delete
const newObject = { ...obj }; Object.keys(newObject).forEach(key => { delete newObject[key]; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
create new object
directly delete

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its various components.

**Benchmark Overview**

The benchmark, named "delete property of object vs create new object", measures the performance difference between two approaches: creating a new object by copying an existing one and directly deleting properties from the original object. This benchmark tests the efficiency of these approaches in JavaScript.

**Options Compared**

There are two options being compared:

1. **Create New Object**: This approach involves creating a new object using the spread operator (`{ ...obj }`) or `Object.keys()` and `reduce()`. The idea is to create a shallow copy of the original object, which allows for the direct deletion of properties.
2. **Directly Delete**: This approach directly deletes properties from the original object using `delete` keyword.

**Pros and Cons**

### Create New Object

Pros:

* Creates a shallow copy of the original object, which can be more efficient if the object contains many small properties.
* Allows for easy deletion of properties without modifying the original object.

Cons:

* May create unnecessary intermediate objects, depending on the JavaScript engine used.
* May have performance implications due to the creation of new objects.

### Directly Delete

Pros:

* Does not create any additional objects, which can be beneficial for memory-constrained environments.
* Can be faster if the original object contains many small properties that are quickly deleted.

Cons:

* Modifies the original object directly, which may have unintended consequences in certain scenarios.
* May involve more complex code and additional checks to ensure property deletion is safe.

**Library Usage**

None of the benchmark cases explicitly uses any external libraries.

**Special JS Features/Syntax**

Neither of the two approaches requires special JavaScript features or syntax. The benchmark focuses on general JavaScript concepts, making it accessible to a wide range of developers.

**Other Alternatives**

Other alternatives for creating new objects or deleting properties from an object include:

* Using `Object.assign()` to create a shallow copy
* Utilizing a library like Lodash's `cloneDeep()` function to create deep copies
* Employing a more complex approach involving property iteration and mutation using `for...in` loops

Keep in mind that the performance difference between these approaches may vary depending on the specific use case, JavaScript engine, and system configuration.

In summary, this benchmark provides a straightforward comparison of two common approaches to creating new objects and deleting properties from an object in JavaScript. The results can help developers optimize their code for better performance and resource usage in various scenarios.

Related benchmarks:

delete property of object vs create new object (version: 0)

Comparing performance of: create new object vs directly delete

Created: 4 years ago by: Registered User

Jump to the latest result

create new object

directly delete

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):