Let's dive into the explanation.

Benchmark Definition

The benchmark is called "jQuery 3.3.1 slim by id vs Document.getElementById". This name indicates that we're comparing two different ways to select an HTML element using its ID, one using jQuery (a popular JavaScript library) and the other using native JavaScript (Document.getElementById()).

Description

The description explains that this benchmark is measuring the speed of getting an element by ID using jQuery versus using native JavaScript.

Script Preparation Code

There's no special script preparation code for this benchmark. However, the HTML preparation code is provided, which includes a jQuery library reference and a simple HTML div with an ID "testElement".

Individual Test Cases

We have two test cases:

1. jQuery: This test uses the $ function to select the element by ID ($("#testElement")[0]) and then retrieves its className property.
2. Vanilla JS: This test uses the native JavaScript method document.getElementById() to select the element and then retrieves its className property.

Latest Benchmark Result

The results show two executions per second (EPS) values for each test case:

1. Vanilla JS: 10104743.0 EPS
2. jQuery: 3609479.5 EPS

This means that, in this specific browser and environment, selecting an element by ID using native JavaScript (Document.getElementById()) is approximately 2.8 times faster than using jQuery.

Library and Features

The benchmark uses the popular jQuery library, which provides a concise way to select HTML elements. The $ function is a key part of jQuery's API.

In this case, the test uses the $ function to select an element by ID ($("#testElement")[0]). This approach is often referred to as a "selector" in jQuery.

Pros and Cons

Using jQuery for selecting elements has some pros:

• Concise syntax
• Easy to use for complex selections

However, it also has cons:

• Additional library overhead (in this case, ~2.8x slower than native JavaScript)
• Potential errors if not used correctly

Native JavaScript methods like Document.getElementById() have their own advantages and disadvantages:

Pros:

• Faster execution (~2.8x faster in this case)
• More control over the selection process

Cons:

• Less concise syntax
• Requires more code to achieve similar results

Alternatives

If you need to select an element by ID, you can use native JavaScript methods like Document.getElementById() or document.querySelector('#testElement'). If you're already using jQuery in your project, you can stick with it. However, if performance is a concern, switching to native JavaScript methods might be worth considering.

Remember that this benchmark result is specific to the provided environment and browser version. Results may vary depending on your own setup.