js document.getelementsbyclassname modify innertext
<body> <p class="demo">JavaScript can change the content of an HTML element.</p> <p class="demo">Yolo</p> <button type="button" onclick="myFunction()">Click Me!</button> <script> function myFunction() { x=document.getElementsByClassName("demo"); // Find the elements for(var i = 0; i < x.length; i++){ x[i].innerText="Hello JavaScript!"; // Change the content } } </script> </body>