Benchmark: delete vs spread

Script Preparation code:

var query = {
    dates: [],
    latestDate: 'whatever'
};
var query2 = {
    current: {
        query: {
            dates: [1, 2, 3],
            latestDate: 'whatever2'
        }
    }
}

Tests:

delete
let storeQuery = { ...query }; let latestQuery = { ...query2.current?.query }; delete storeQuery.latestDate; delete latestQuery.latestDate;
spred
const { latestDate: remove, ...storeQuery } = query; const { latestDate: remove1, ...latestQuery } = query2.current?.query || {};

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
delete
spred

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark definition and test cases measure the performance difference between two approaches: using `delete` and using object spread (`...`) when deleting properties from an object.

**What is being tested?**

The benchmark tests how fast it is to delete properties from objects in different ways:

1. **Using `delete`**: The first test case uses the `delete` keyword to remove a property from two separate objects, `storeQuery` and `latestQuery`. This approach requires the browser to perform a runtime check on the object's prototype chain and potentially reassign the deleted property.
2. **Object spread (`...`)**: The second test case uses object spread to create new objects with the desired properties and then deletes them using the `delete` keyword. This approach creates new objects instead of modifying the original, which may bypass some of the overhead associated with deleting properties.

**Options compared**

The benchmark compares two options:

* **Using `delete`**: This approach requires the browser to perform runtime checks on the object's prototype chain and potentially reassign the deleted property.
* **Object spread (`...`)**: This approach creates new objects instead of modifying the original, which may bypass some of the overhead associated with deleting properties.

**Pros and Cons**

* **Using `delete`**:
	+ Pros: Simple and straightforward implementation.
	+ Cons: May require runtime checks on the object's prototype chain, potentially causing performance issues.
* **Object spread (`...`)**
	+ Pros: Can bypass some of the overhead associated with deleting properties by creating new objects instead of modifying the original.
	+ Cons: Requires additional memory allocation for the new objects and may have a higher constant factor due to object creation.

**Library usage**

There is no explicit library used in this benchmark. However, it's worth noting that both `delete` and object spread are part of the standard JavaScript syntax.

**Special JS feature or syntax**

No special features or syntax are used beyond standard JavaScript operations. The benchmark only relies on basic JavaScript concepts, making it accessible to a wide range of software engineers.

**Other alternatives**

If you're interested in exploring alternative approaches, consider the following:

* **Using `Object.prototype.delete`**: This method is not widely supported and may have compatibility issues with older browsers.
* **Using a custom delete function**: You can create a custom delete function using `Object.defineProperty` or `Object.create`. However, this approach requires more boilerplate code and may not be as efficient as the `delete` keyword or object spread.

In conclusion, the benchmark highlights the performance differences between two common approaches to deleting properties from objects in JavaScript. The results indicate that using object spread (`...`) can outperform using the `delete` keyword for certain use cases, although the constant factor and memory allocation may make it less efficient in all cases.

Related benchmarks:

delete vs spread (version: 0)

Comparing performance of: delete vs spred

Created: 4 years ago by: Guest

Jump to the latest result

delete

spred

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):