Benchmark: Delete vs set undefined Properties

Script Preparation code:

var objA = {a:1, b:2, c:3, d:4};
var objB = {a:1, b:2, c:3, d:4};
delete objA.a;
delete objA.b;
delete objA.c;
delete objA.d;
objB.a = undefined;
objB.b = undefined;
objB.c = undefined;
objB.d = undefined;

function doNothing(objin){}

Tests:

Deleted
Object.entries(objA);
Set undefined
Object.entries(objB);
Iterate deleted
for(let a in objA) doNothing(a)
Iterate set undefined
for(let b in objB) doNothing(b)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Deleted
Set undefined
Iterate deleted
Iterate set undefined

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website where users can create and run JavaScript microbenchmarks to compare the performance of different approaches in various scenarios. The benchmark you provided tests four individual test cases:

1. "Deleted": Measures the performance of `Object.entries(objA)` after deleting properties from object `objA`.
2. "Set undefined": Measures the performance of `Object.entries(objB)` after setting properties in object `objB` to `undefined`.
3. "Iterate deleted": Measures the performance of iterating over object `objA` using a `for...in` loop after deleting its properties.
4. "Iterate set undefined": Measures the performance of iterating over object `objB` using a `for...in` loop after setting its properties to `undefined`.

**Options Compared**

The benchmark compares four options:

1. **Deleted**: Delete properties from object `objA` before measuring the performance of `Object.entries(objA)`.
2. **Set undefined**: Set properties in object `objB` to `undefined` before measuring the performance of `Object.entries(objB)`.

**Pros and Cons**

* **Deleted**:
	+ Pros: This approach simulates a common scenario where an object's properties are deleted, which can affect the performance of subsequent operations.
	+ Cons: Deleting properties can lead to memory fragmentation and potentially slow down garbage collection.
* **Set undefined**: This approach simulates setting properties to `undefined`, which is a common operation in JavaScript. However, it may not accurately represent real-world scenarios where objects are modified frequently.

**Library**

In the benchmark preparation code, the following library is used:

* None explicitly mentioned, but the `Object.entries()` method is used, which is a built-in method of the `Object` class.

**Special JS Features or Syntax**

The benchmark uses the `doNothing` function, which is defined in the script preparation code. However, there is no indication that this function does anything specific or special beyond simply not doing anything (hence the name).

**Other Alternatives**

To run this benchmark, you can create a new benchmark on MeasureThat.net and paste the provided JSON data into the "Benchmark Definition" field. You will also need to provide your own script preparation code, which should include the `doNothing` function.

If you want to run similar benchmarks, you can try:

* Using different browsers or versions
* Testing other object methods, such as `Object.keys()` or `JSON.stringify()`
* Simulating different scenarios, such as adding or removing properties from an object

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:104.0) Gecko/20100101 Firefox/104.0

Browser/OS: Firefox 104 on Windows

View result in a separate tab

Test name	Executions per second
Deleted	17692076.0 Ops/sec
Set undefined	5162305.5 Ops/sec
Iterate deleted	115074440.0 Ops/sec
Iterate set undefined	44894736.0 Ops/sec

Related benchmarks:

Delete vs set undefined Properties (version: 0)

Comparing performance of: Deleted vs Set undefined vs Iterate deleted vs Iterate set undefined

Created: 3 years ago by: Guest

Jump to the latest result

Deleted

Set undefined

Iterate deleted

Iterate set undefined

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):