It is not directly possible to add an onclick attribute to an element with a specific HTML class name from within PHP code. PHP runs on the server side; no PHP code is executed after the page is loaded in the user’s browser. Therefore, interacting directly with client-side elements is primarily done using JavaScript.
However, you can include an onclick attribute when generating HTML elements using PHP. For example, if your PHP code creates an HTML button, you can add an onclick event handler to this button.
In this example, we created a button with class my-class and attached a JavaScript function called myFunction() to the button as an onclick event.
If you want to add an onclick attribute to an existing HTML element, you must use JavaScript to find the element after loading the page and add an event listener.
This JavaScript code finds all elements with a specific class after the document is loaded and adds an onclick event. Because this method runs on the client side, it can be applied to elements that already exist on the page.