java - do while 循环在我不希望它循环时循环

Question

我有一个 do while 循环，但它不起作用。正如您在我的代码中看到的，如果变量“choice”不等于 p 或 n，则应该循环。即使我选择等于 p 或 n，它也至少循环一次。是我的位置不好还是什么？

    do{
        System.out.println("Enter the name of the contact you would like to update");
        name = sc.nextLine();
        System.out.println("Would you like to update their name(press n) or phone"
                + "number(press p)?");
        choice = sc.nextLine();
        if(choice.equalsIgnoreCase("n")){
            System.out.println("Enter the new name for the contact");
            String name1 = sc.nextLine();
            SQL.updateName(name, name1);
            c = SQL.searchByName(name1);
            if(c != null)
                System.out.printf("Name: %s\t Phonenumber: %s\n", c.getName(), c.getPhone());
            else
                System.out.println(name+" does not exist");
        }
        else if(choice.equalsIgnoreCase("p")){
            System.out.println("Enter the new number for "+name);
            phone = sc.nextLine();
            SQL.updateNumber(name, phone);
            c = SQL.searchByPhone(phone);
            if(c != null)
                System.out.printf("Name: %s\t Phonenumber: %s\n", c.getName(), c.getPhone());
            else
                System.out.println(name+" does not exist");
        }
        }
        while(choice.equalsIgnoreCase("p") == false || choice.equalsIgnoreCase("n") == false);

Answer 1

你的逻辑不正确；任何选择将始终不等于“p”或不等于“n”。仅当它不是 "p" 且 不是 "n" 时才需要循环。使用&&:

while(choice.equalsIgnoreCase("p") == false && choice.equalsIgnoreCase("n") == false);