How Can I Use getElementsByClassName to Change Element Styles on Events?

getElementsByClassName to Change Element Styles on Event

When working with HTML elements, getElementsByClassName can be employed to manipulate multiple elements that share the same class name. In this context, the issue arises when attempting to alter the style of all elements with a specific class when an event occurs.

To address this challenge, the first step is to understand that getElementsByClassName returns an array of matching elements, not a single object. Thus, it's necessary to iterate through the returned array and apply the style changes to each individual element.

Additionally, note that ID attributes in HTML must be unique within a page. If multiple elements have the same ID, it may lead to unexpected behavior. To resolve this, consider using unique IDs for each element or explore alternative methods such as handling events through event listeners or using classes.

Here's an example to demonstrate a more robust approach:

<code class="javascript">var elements = document.getElementsByClassName('my-class');
for (var i = 0; i < elements.length; i++) {
  elements[i].style.backgroundColor = 'red';
}</code>

In this example, all elements with the class name 'my-class' will have their background color set to red. This method ensures that all matching elements are affected by the style change and avoids any ID-related issues.

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