How can I stop the browser back button using JavaScript?

Question

I am doing an online quiz application in PHP. I want to restrict the user from going back in an exam.

I have tried the following script, but it stops my timer.

Answer 1

This seems to have worked for us in disabling the back button on the browser, as well as the backspace button taking you back.

history.pushState(null, null, $(location).attr('href'));
    window.addEventListener('popstate', function () {
        history.pushState(null, null, $(location).attr('href'));
    });