为了使客户端菜单在完成后返回登录菜单，请添加两个while循环，一个用于登录屏幕，一个用于客户端屏幕，如下所示：
boolean loginScreenDone=false;while(!loginScreenDone) { System.out.println("--------Login Screen--------"); System.out.println("Enter C for client and E for employee: "); String login = s.nextLine(); if ("C".equals(login)) { boolean clientScreenDone=false; while(!clientScreenDone) { System.out.println("Welcome to the client screen"); System.out .println("There are 3 Lotteries (Lotto, Jackpot and National)"); System.out.println("Please select one (L, J, N) or E to exit: "); String select = s.nextLine(); switch (select) { case "L": //call a method to handle Lotto here break; case "J": //call a method to handle Jackpot here break; case "N": //call a method to handle National here break; case "E": clientScreenDone=true; break; default: System.out.println("Invalid Selection"); break; } }}
