JavaScript: How to Focus Tab or Window - Quick Guide

When developing web applications, it's common to have the need to focus a particular tab or window programmatically. Fortunately, JavaScript provides us with a straightforward solution to achieve this.

To focus a tab or window, we can use the `window.focus()` method. This method is available on any `Window` object, which includes the global `window` object as well as any `iframe` or pop-up windows.

To focus the current tab or window, we simply need to call `window.focus()` from within the context of that tab or window. For example:

// focus the current window
window.focus();

If we want to focus a different tab or window, we first need to obtain a reference to that window. We can do this using the `window.open()` method, which opens a new window and returns a reference to it. For example:

// open a new window and obtain a reference to it
var newWindow = window.open('https://www.example.com');

// focus the new window
newWindow.focus();

Alternatively, if we already have a reference to a window (e.g. from an `iframe` or pop-up), we can simply call `windowReference.focus()` on that window reference.

In summary, to focus a tab or window in JavaScript, we can use the `window.focus()` method. If we want to focus a specific window, we first need to obtain a reference to it using `window.open()` or from an existing reference.