JAVA 有关IF问题

JAVA 有关IF问题

System.out.print("你的选择:");
 Scanner scanner = new Scanner(System.in);
        String choose = scanner.nextLine();
        while(!"A".equals(choose)&&!"B".equals(choose)&&!"C".equals(choose)){
            System.out.println("只能输入ABC");
            choose = scanner.nextLine();
        }
        if("A".equals(choose)){
            System.out.println("1+1");
        }else if("B".equals(choose)){
            System.out.println("1-1");
        }else if("C".equals(choose)){
            System.out.println("1X1");
        }