Browser back and forward button event javascript

1. What event is fired when the back button of a browser is pressed?
2. How to implement back and forward functionality like browser?
3. How to detect back button click of mobile in JavaScript?

What event is fired when the back button of a browser is pressed?

The popstate event is fired each time when the current history entry changes (user navigates to a new state). That happens when user clicks on browser's Back/Forward buttons or when history. back() , history.

How to implement back and forward functionality like browser?

Initialize currentStateURL that will store the current URL of the Browser. Initialize two stacks forwardStack and backwardStack that will store the sequence of URLs accessed when the forward and the backward buttons are pressed respectively.

How to detect back button click of mobile in JavaScript?

According to this source, to detect the 'back' key, KEYCODE_BACK = 4 on Android.