Benchmark: delete vs undefined1

Tests:

undefined
var obj = {}; for(var i = 0; i < 1000;i++) { obj['a' + i] = i; } for(var i = 0; i < 1000;i++) { obj['a' + i] = undefined; }
delete
var obj = {}; for(var i = 0; i < 1000;i++) { obj['a' + i] = i; } for(var i = 0; i < 1000;i++) { delete obj['a' + i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
undefined
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.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

The provided benchmark measures the performance difference between deleting properties from an object (`delete`) and setting them to `undefined` (`undefined`). The test creates an empty object, iterates 1000 times, and assigns a value to each property with a unique name (e.g., `'a' + i`). Then, it performs either the deletion or assignment of `undefined` operation on these properties.

**Options compared:**

There are two options being compared:

1. **Delete (`delete`)**: This option uses the built-in `delete` operator to remove properties from an object.
2. **Undefined (`undefined`)**: This option sets the value of a property to `undefined`.

**Pros and cons of each approach:**

* **Delete (`delete`)**:
	+ Pros:
		- Efficient, as it only updates the internal property reference without creating a new property.
		- Can be faster since it doesn't create a new property with `undefined` value.
	+ Cons:
		- May not work correctly if the property is not already defined in the object (e.g., will create a new property).
		- Some older browsers may not support it.
* **Undefined (`undefined`)**:
	+ Pros:
		- Works correctly even if the property is not already defined in the object (creates a new property with `undefined` value).
		- Wide browser support.
	+ Cons:
		- Creates a new property with `undefined` value, which can lead to increased memory usage.
		- May be slower due to creating a new property.

**Library and special JS features:**

There are no libraries or special JavaScript features being used in this benchmark. The test only relies on the standard JavaScript language features.

**Alternative approaches:**

If you wanted to explore alternative approaches, here are a few options:

* **Using `delete` with a different syntax**: In some older versions of JavaScript (e.g., ECMAScript 3), the `delete` operator was not available. An alternative approach would be to use the `object.delete()` method (introduced in ECMAScript 2020) or the `Object.prototype.hasOwnProperty.call(obj, prop)` trick.
* **Using a library or framework**: Some libraries, like Lodash, provide functions for deleting properties from objects. However, this would likely introduce additional overhead and might not be necessary for a simple benchmark like this one.
* **Using a different data structure**: Instead of using an object, you could use an array with 1000 elements and delete the elements individually. This would change the nature of the benchmark but still test the performance of deleting or setting to `undefined` values.

Keep in mind that these alternative approaches might not be relevant for this specific benchmark, as it's focused on comparing two specific JavaScript operations.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36

Browser/OS: Chrome 78 on Linux

View result in a separate tab

Test name	Executions per second
undefined	2242.7 Ops/sec
delete	2799.4 Ops/sec

Related benchmarks:

delete vs undefined1 (version: 0)

Comparing performance of: undefined vs delete

Created: 4 years ago by: Guest

Jump to the latest result

undefined

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):