Benchmark Overview

The provided JSON represents a JavaScript microbenchmark created on MeasureThat.net. The benchmark compares the performance of three different methods to retrieve the width of an HTML element: clientWidth, offsetWidth, and scrollWidth.

Test Case 1: clientWidth

• Description: Retrieves the width of an element relative to its parent element.
• Options compared: Not specified, but likely against other methods (e.g., offsetWidth, scrollWidth) for a direct comparison.
• Pros and Cons:
  • Pros: Often faster than offsetWidth or scrollWidth since it only needs to calculate the width relative to its parent element.
  • Cons: May not reflect the full width of the element if the parent element has a different width.

Test Case 2: offsetWidth

• Description: Retrieves the width of an element including any borders, margins, and padding.
• Library: window.getComputedStyle is used to access the computed style of the element.
• Pros and Cons:
  • Pros: Provides an accurate representation of the element's width, including any additional attributes.
  • Cons: May be slower than clientWidth since it needs to access and calculate more information.

Test Case 3: scrollWidth

• Description: Retrieves the width of an element after scrolling to its bottom or top edge.
• Library: Not explicitly mentioned, but likely relying on browser APIs (e.g., Element.scrollWidth).
• Pros and Cons:
  • Pros: Provides a more accurate representation of the element's full width.
  • Cons: May be slower than offsetWidth due to additional calculations.

Special Considerations

The benchmark does not use any special JavaScript features or syntax that would require specific attention. However, it is worth noting that the use of window.getComputedStyle can introduce additional overhead compared to accessing an element's style directly.

Other Alternatives

Some alternative methods to compare with these three might include:

• getBoundingClientRect().width
• Using a CSS query (e.g., document.getElementById('teste').cssWidth)
• Measuring the element's width using a rendering engine API (e.g., CanvasRenderingContext2D.measureText())

Keep in mind that these alternatives may not be as straightforward to implement and might introduce additional overhead or complexities.

Benchmark Preparation Code Explanation

The script preparation code snippet sets up a test environment by:

1. Defining a variable _teste_n with the value '123px'.
2. Accessing the computed style of an HTML element (document.getElementById('teste')) using window.getComputedStyle.

This setup allows the benchmark to test the performance of retrieving the width of an element in different contexts.

Latest Benchmark Result Explanation

The latest benchmark result provides a summary of the execution times for each test case:

• offsetWidth: 607.311 seconds
• clientWidth: 444.607 seconds
• scrollWidth: 600.328 seconds

These results indicate that, on this specific setup and device, clientWidth is the fastest method to retrieve an element's width, followed by scrollWidth, and then offsetWidth.