$userID = Auth::getUserID();
if (Auth::getUserID() !== NULL) { // Do something if user is authenticated } else { // Do something else if user is not authenticated }This code checks if the currently authenticated user has an ID assigned to them. If they do, the first block of code is executed, otherwise the second block is executed. Based on the naming convention and functionality of the method, it is likely that this code is part of an authentication package or library.