Benchmark: Delete vs Undefined with Multiple Properties

Script Preparation code:

var obj = {
    property : "value",
    propertyTwo: "value2"
};

Tests:

Delete
delete obj.property
Undefined
obj.property = undefined;
null
obj.property = null;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Delete
Undefined
null

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what's being tested.

**Benchmark Definition**

The benchmark is testing three different approaches for deleting or setting properties on an object in JavaScript:

1. **Delete**: `delete obj.property`
2. **Undefined**: `obj.property = undefined;`
3. **Null**: `obj.property = null;`

These tests aim to compare the performance of each approach, specifically focusing on deletion.

**Options Compared**

The benchmark is comparing three options for deleting or setting properties:

1. Using the `delete` keyword
2. Setting a property to `undefined` using assignment (`=`)
3. Setting a property to `null` using assignment (`=`)

**Pros and Cons of Each Approach**

Here's a brief overview of each approach:

* **Delete**: This is the most straightforward way to delete a property from an object. It directly removes the property without creating a new reference.
	+ Pros: Efficient, no memory allocation or copying involved
	+ Cons: Can lead to unexpected behavior if used with some data structures (e.g., arrays)
* **Undefined**: Setting a property to `undefined` creates a new weak reference to the property. When the object is garbage collected, this weak reference will be cleared.
	+ Pros: Memory efficient, can help prevent memory leaks
	+ Cons: Can lead to unexpected behavior if not used carefully (e.g., when using `delete` on a property that's already been set to `undefined`)
* **Null**: Setting a property to `null` is similar to setting it to `undefined`, but creates a strong reference instead.
	+ Pros: Similar benefits as `undefined`
	+ Cons: Still may lead to unexpected behavior if not used carefully

**Libraries and Special JS Features**

There are no external libraries or special JavaScript features mentioned in the benchmark definition.

**Other Considerations**

When considering these approaches, keep in mind:

* In modern JavaScript engines, most property deletions will result in a reference count of 1 for each property, making it unlikely that the property will be immediately removed from memory. However, this might not always hold true for older browsers or specific use cases.
* Using `delete` with arrays can lead to unexpected behavior and may cause some operations (like `push`) to fail silently.

**Alternatives**

Other alternatives for deleting or setting properties include:

* Using a library like Lodash's `deleteProperty()` function, which might offer additional benefits or workarounds not covered by the benchmark.
* Considering alternative data structures, such as Maps or Sets, if you're dealing with large datasets and want to optimize memory usage.

In summary, this benchmark aims to compare the performance of three different approaches for deleting or setting properties on objects: `delete`, `obj.property = undefined;`, and `obj.property = null;`. The results will help users understand the relative efficiency of each approach in JavaScript.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36

Browser/OS: Chrome 105 on Windows

View result in a separate tab

Test name	Executions per second
Delete	12753831.0 Ops/sec
Undefined	5194556.0 Ops/sec
null	13989244.0 Ops/sec

Related benchmarks:

Delete vs Undefined with Multiple Properties (version: 0)

Compare JavaScript deletion on object vs setting to undefined.

Comparing performance of: Delete vs Undefined vs null

Created: 2 years ago by: Guest

Jump to the latest result

Delete

Undefined

null

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):