Benchmark: objects delete vs null vs undefined vs void 0 vs Object.create(null)

Tests:

null
var a = 999; for(var i = 0; i < 1000;i++) { const b = {a:null}; }
undefined
var a = 999; for(var i = 0; i < 1000;i++) { const b = {a: undefined}; }
Object.create(null)
var a = 999; for(var i = 0; i < 1000;i++) { const b = {a: Object.create(null)}; }
void 0
var a = 999; for(var i = 0; i < 1000;i++) { const b = {a: void 0}; }
delete
var a = 999; for(var i = 0; i < 1000;i++) { const b = {a: void 0}; delete b.a; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
null
undefined
Object.create(null)
void 0
delete

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Measuring the performance of different approaches to delete or set a property on an object can be a complex task, and there are various ways to achieve this in JavaScript.

The benchmark provided by MeasureThat.net compares four approaches:

1. **Using the `delete` operator**: This is one of the most straightforward approaches. The `delete` operator is used to remove a property from an object. In this case, the code `const b = {a: undefined}; delete b.a;` attempts to delete the `a` property from the object `b`.

Pros:
    - Simple and easy to understand.
    - Works in most browsers.

Cons:
    - Can be slower than other approaches because it involves an additional operation (the deletion itself).
    - May not be as efficient in certain situations, such as when dealing with large objects or complex property names.

2. **Using `undefined`**: Setting a property to `undefined` can achieve similar results to using the `delete` operator. The code `const b = {a: undefined};` sets the `a` property of the object `b` to `undefined`, effectively deleting it.

Pros:
    - Can be faster than using the `delete` operator because it does not involve an additional operation.
    - Works in most browsers.

Cons:
    - May not work as expected if the property is used elsewhere in the code (e.g., as a function argument).
    - Does not provide any information about why the property was deleted, which might be useful for debugging purposes.

3. **Using `void 0`**: `void 0` is equivalent to `undefined`, but it can provide more clarity and readability in certain situations. The code `const b = {a: void 0};` sets the `a` property of the object `b` to `undefined`.

Pros:
    - Provides more explicit information about why the property was deleted (because it's being set to `undefined`, not just assigned a value).
    - Works in most browsers.

Cons:
    - May be slower than using `undefined` due to the additional operator.
    - Similar limitations as with using `undefined`.

4. **Using `Object.create(null)`**: This approach creates an object that inherits from `{}` but does not have any properties of its own. The code `const b = Object.create(null); b.a = undefined;` sets a property on an object created by `Object.create(null)`, effectively deleting it.

Pros:
    - Can be more efficient than using the other approaches because it doesn't involve assigning a value to the property.
    - Provides more information about why the property was deleted (because it's being set on an object that didn't have any properties to begin with).

Cons:
    - May not work as expected in all browsers or situations (e.g., due to limitations in how `Object.create(null)` behaves).
    - Requires understanding of how `Object.create(null)` works and its implications.

In general, using the `delete` operator or setting a property to `undefined` is likely to be faster than the other approaches but may not provide as much information about why the property was deleted. Using `void 0` can provide more explicit information but might be slightly slower due to the additional operator. Creating an object with `Object.create(null)` can be more efficient but requires understanding of its behavior and limitations.

As for libraries or special JavaScript features, there are none explicitly mentioned in this benchmark. However, it's worth noting that some browsers may optimize certain aspects of these operations under the hood (e.g., using caching or other internal optimizations), which could affect the results of a benchmark.

Other alternatives to consider:

* Using `Object.defineProperty` with `{ enumerable: false }` to set properties on an object without making them enumerable, effectively deleting them.
* Using `Symbol` objects and `Symbol.for()` to create and use unique symbols that can be used as property names instead of strings or numbers, potentially optimizing for certain scenarios.
* Optimizing the loop iteration logic itself (e.g., reducing the number of iterations), which could affect the overall performance of the benchmark.

Keep in mind that these alternatives might not directly address the specific question being asked and may require significant changes to the code being benchmarked.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36

Browser/OS: Chrome 118 on Windows

View result in a separate tab

Test name	Executions per second
null	1313453.9 Ops/sec
undefined	8066.1 Ops/sec
Object.create(null)	6898.2 Ops/sec
void 0	1546655.1 Ops/sec
delete	11291.9 Ops/sec

Related benchmarks:

objects delete vs null vs undefined vs void 0 vs Object.create(null) (version: 0)

delete vs null vs undefined vs void 0 vs Object.create(null)

Comparing performance of: null vs undefined vs Object.create(null) vs void 0 vs delete

Created: one year ago by: Guest

Jump to the latest result

null

undefined

Object.create(null)

void 0

delete

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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