Benchmark: test delete - MeasureThat.net

Script Preparation code:

var o = { p: "p" }

Tests:

delete o.p
delete o.p;
o.p = undefined
o.p = undefined;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
delete o.p
o.p = undefined

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36

Browser/OS: Chrome 90 on Windows

View result in a separate tab

Test name	Executions per second
delete o.p	7353762.5 Ops/sec
o.p = undefined	4535490.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark JSON and explain what's being tested, compared, and the pros/cons of different approaches.

**Benchmark Definition**

The benchmark definition specifies two JavaScript expressions to be executed:

1. `delete o.p;`
2. `o.p = undefined;`

These expressions test the deletion of a property from an object using the `delete` operator versus assigning the property a value of `undefined`.

**Script Preparation Code**

The script preparation code is: `"var o = { p: \"p\" };"`

This sets up a simple JavaScript object named `o` with a property `p` and assigns it the string value `"p"`.

**Html Preparation Code**

There is no HTML preparation code, which means that this benchmark only tests pure JavaScript expressions.

**Library Usage**

Neither of the test cases uses any external libraries. The `delete` operator and property assignment are built-in JavaScript features.

**Special JS Feature or Syntax**

The `delete` operator is a special feature in JavaScript that allows deleting a property from an object without throwing an error if the property does not exist. This feature was introduced in ECMAScript 2015 (ES6).

**Benchmark Preparation Code and Individual Test Cases**

For each test case, we have:

1. A benchmark definition specifying a single JavaScript expression to be executed.
2. The script preparation code sets up a simple object `o` with the required property.
3. No HTML preparation code is needed for these pure JavaScript expressions.

**Latest Benchmark Result**

The latest benchmark result shows that:

* Chrome 90 on Desktop (Windows) executes `delete o.p;` approximately 2.38 times faster than executing `o.p = undefined;`.

**Pros and Cons of Different Approaches**

1. **Using the `delete` operator**: This approach can be faster because it avoids the need to check if the property exists using the `in` operator or `hasOwnProperty()` method.
	* Pros: Can be faster for simple cases, reduces overhead.
	* Cons: May not work as expected in certain scenarios (e.g., when the object is already deleted), may lead to unexpected behavior due to the lack of error handling.
2. **Assigning a value of `undefined`**: This approach checks if the property exists before assigning it a value.
	* Pros: More robust and safer, avoids potential issues with deleting properties that are not intended for deletion.
	* Cons: May be slower in simple cases due to the additional check.

**Other Alternatives**

Some alternative approaches could have been used, such as:

1. Using `delete` and then immediately reassigning the property using the original value or a default value.
2. Using a library like Lodash's `omit` function to remove properties from an object without deleting them entirely.
3. Using a different data structure, such as an array, instead of an object.

However, these alternatives would likely increase the complexity and overhead of the benchmarking process, potentially skewing the results in favor of one approach over another.

Related benchmarks:

test delete (version: 0)

Comparing performance of: delete o.p vs o.p = undefined

Created: 3 years ago by: Guest

Jump to the latest result

delete o.p

o.p = undefined

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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