Benchmark: Performance of delete on large arrays vs set undefined

Script Preparation code:

var N0 = 50855;

Tests:

50855
const N = N0; const o = {}; for ( let i = 0; i < N; i++ ) { o[i] = i; } for ( let i = 0; i < N; i++ ) { delete o[i]; }
50856
const N = N0; const o = {}; for ( let i = 0; i < N; i++ ) { o[i] = i; } for ( let i = 0; i < N; i++ ) { o[i] = undefined; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
50855
50856

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its various components.

**Benchmark Purpose**

The purpose of this benchmark is to compare the performance of two approaches:

1. **Delete on large arrays**: This approach uses the `delete` keyword to remove elements from an array.
2. **Set undefined on large arrays**: This approach sets the value of individual elements in the array to `undefined`.

**Options Compared**

The two options being compared are:

* `delete o[i];`: This is the traditional way of deleting elements from an array using the `delete` keyword.
* `o[i] = undefined;`: This approach involves setting each element individually to `undefined`.

**Pros and Cons**

1. **Delete on large arrays (delete)**:
	* Pros: This method is more straightforward and has been widely used for decades.
	* Cons: It can be slower than the alternative approach because it requires searching for the key in the array's internal structure.
2. **Set undefined on large arrays (o[i] = undefined)**:
	* Pros: This approach is generally faster because it only sets each element to `undefined`, without the overhead of searching for the key.
	* Cons: It may not be as intuitive or widely supported, especially in older browsers.

**Library and Special JS Features**

In this benchmark, there is no specific library being tested. However, note that the use of `const` (the "const" keyword) is a relatively recent feature in JavaScript, introduced in ECMAScript 2015 (ES6). This means that older browsers may not support it.

**Alternative Approaches**

Other approaches to delete elements from an array could include:

* Using a library like Lodash or Ramda, which provide optimized functions for array manipulation.
* Utilizing modern browser features like `Array.prototype.forEach` with the `delete` keyword (although this is still a relatively new feature and may not be supported in older browsers).
* Implementing a custom solution using JavaScript's built-in data structures, such as linked lists or hash tables.

**Benchmark Preparation Code**

The script preparation code provided creates an array of size `N0` (50855) and populates it with consecutive integers from 0 to `N-1`. This is done to provide a large enough dataset for the benchmark.

**Individual Test Cases**

Each test case consists of two parts:

* The `Benchmark Definition`: This defines the JavaScript code that will be executed during the benchmark. For each test case, there are two definitions:
	+ `50855`: This deletes elements from an array using the traditional `delete` keyword.
	+ `50856`: This sets individual elements to `undefined`.
* The `Test Name`: Each test case has a unique name based on its identifier (`N0` or `N-1`).

Related benchmarks:

Performance of delete on large arrays vs set undefined (version: 0)

Comparing performance of: 50855 vs 50856

Created: 7 years ago by: Guest

Jump to the latest result

50855

50856

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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