Benchmark: test5 delete - MeasureThat.net

Script Preparation code:

var o = { p: "p" };

Tests:

delete o.p
delete o.p;
delete o["p"]
delete o["p"];
o.p = undefined
o.p = undefined;
o["p"] = undefined;
o["p"] = undefined;
o.p = null
o.p = null;
o["p"] = null
o["p"] = null;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
delete o.p
delete o["p"]
o.p = undefined
o["p"] = undefined;
o.p = null
o["p"] = null

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Measuring the performance of JavaScript deletions can be an interesting and useful benchmark.

**Overview**

The provided JSON represents a set of test cases that measure the performance of deleting properties from an object in JavaScript. The tests compare different approaches to delete properties, including `delete`, bracket notation (`[]`), assigning a value of `undefined`, or `null`.

**Options Compared**

The following options are compared:

1. **`delete o.p;`**: This is the traditional way of deleting a property using the `delete` keyword.
2. **`o[\"p\"] = undefined;`**: This method uses bracket notation to access and delete the property, followed by assigning `undefined` to it.
3. **`o.p = null;`**: This approach assigns `null` to the property instead of deleting it.

**Pros and Cons**

1. **`delete o.p;`**:
	* Pros: Fast and efficient, as it only updates the property's metadata.
	* Cons: May not work in all cases, such as when the property is accessed or modified after deletion.
2. **`o[\"p\"] = undefined;`**:
	* Pros: Works even if the property is accessed or modified after deletion.
	* Cons: May be slower due to the extra operation of assigning `undefined`.
3. **`o.p = null;`**:
	* Pros: Ensures the property is no longer accessible, which can be desirable in some cases.
	* Cons: Assigns a new value, which may not be necessary or intended.

**Other Considerations**

When dealing with objects in JavaScript, it's essential to consider how properties are stored and retrieved. In modern browsers, object properties are stored as hash tables (also known as maps), which provide fast lookup and deletion of properties.

However, the behavior of `delete` can vary depending on the context, such as:

* When deleting a property from an object that is being accessed or modified.
* When the deleted property has already been assigned a new value.

**Library Usage**

None of the provided test cases use any external libraries. The tests only rely on built-in JavaScript features.

**Special JS Features/Syntax**

There are no special JS features or syntax mentioned in the benchmark definition or individual test cases. However, it's worth noting that bracket notation (`[]`) is a common way to access properties in JavaScript, and `delete` can be used with object literals, dot notation, or bracket notation.

**Alternatives**

Other alternatives for deleting properties from objects include:

* Using the `Object.keys()` method to iterate over property names and delete them individually.
* Utilizing the `JSON.stringify()` method to serialize the object and then parse it without specific properties.
* Leveraging modern JavaScript features like `for...in` loops, which provide a more comprehensive way of iterating over an object's properties.

Keep in mind that these alternatives might have different performance characteristics or use cases compared to the options tested in the benchmark.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko

Browser/OS: IE 11 on Windows

View result in a separate tab

Test name	Executions per second
delete o.p	2537540.8 Ops/sec
delete o["p"]	2482627.0 Ops/sec
o.p = undefined	1965695.1 Ops/sec
o["p"] = undefined;	1583233.5 Ops/sec
o.p = null	2236516.8 Ops/sec
o["p"] = null	2272753.2 Ops/sec

Related benchmarks:

test5 delete (version: 0)

Comparing performance of: delete o.p vs delete o["p"] vs o.p = undefined vs o["p"] = undefined; vs o.p = null vs o["p"] = null

Created: 3 years ago by: Guest

Jump to the latest result

delete o.p

delete o["p"]

o.p = undefined

o["p"] = undefined;

o.p = null

o["p"] = null

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):