Toggle between two classes for a <div> element:
document.getElementById("myDIV").classList.toggle("newClassName");
Click the button to toggle between two classes.
<!DOCTYPE html> <html> <head> <style> .mystyle {//from www . j av a 2 s . c om width: 300px; height: 50px; background-color: coral; color: white; font-size: 25px; } .newClassName { width: 400px; height: 100px; background-color: lightblue; text-align: center; font-size: 25px; color: navy; margin-bottom: 10px; } </style> </head> <body> <button onclick="myFunction()">Test</button> <div id="myDIV" class="mystyle"> I am a DIV element </div> <script> function myFunction() { document.getElementById("myDIV").classList.toggle("newClassName"); } </script> </body> </html>