How to Reliably Detect Overflowing Content in HTML Elements?

Detecting Overflowed Content in HTML Elements

Determining whether an HTML element's content has exceeded its boundaries can be a common task when designing web pages. However, the standard method of comparing client dimensions to scroll dimensions doesn't always work when overflow is set to visible, as the values will be identical.

To overcome this issue, the provided JavaScript function temporarily modifies the CSS overflow setting to hidden. This allows us to accurately detect whether the element is truly overflowing its bounds, either vertically or horizontally. Here's the code:

function checkOverflow(el) {
   var curOverflow = el.style.overflow;

   if ( !curOverflow || curOverflow === "visible" )
      el.style.overflow = "hidden";

   var isOverflowing = el.clientWidth < el.scrollWidth 
      || el.clientHeight < el.scrollHeight;

   el.style.overflow = curOverflow;

   return isOverflowing;
}

This function has been tested in major browsers, including Firefox, Internet Explorer, and Chrome, ensuring that it works consistently across platforms. By leveraging this technique, you can now effortlessly check if an HTML element's content is overflowing its allocated space, regardless of scrollbar visibility.

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