Check if page gets reloaded or refreshed in JavaScript

Question

I want to check when someone tries to refresh a page.

For example, when I open a page nothing happens but when I refresh the page it should display an alert.

Answer 1

Here is a method that is supported by nearly all browsers:

if (sessionStorage.getItem('reloaded') != null) {
    console.log('page was reloaded');
} else {
    console.log('page was not reloaded');
}

sessionStorage.setItem('reloaded', 'yes'); // could be anything

It uses SessionStorage to check if the page is opened the first time or if it is refreshed.