Question

我有一个命令行要求用户说（Y / N），并将此值传递给checkResponse方法。

由于某种原因，while循环忽略该值，即使我调试它时显示的值为“Y”。当值设置为“N”时，它也会继续循环。如果我将if语句移动到while语句下面，程序就会中途运行。我可以发送一个初始值“Y”，而while语句将忽略它并开始在其中运行代码。

知道我缺少什么或过度看？

提前致谢。

public void checkResponse(string response, string confirmValue)
{
    Console.WriteLine(response);
    Console.WriteLine(response);
    if (response == "Y")
    {
        return;
    }
    else if (response == "N")
    {
        Environment.Exit(0);
    }
    else
    {
        while ((response != "Y") || (response != "N"))
        {
            Console.Clear();
            Console.WriteLine("\"" + response + "\" is not a valid response.");
            Console.WriteLine();
            Console.WriteLine("You entered:" + confirmValue);
            Console.WriteLine("Is this correct? (Y/N)");
            response = Console.ReadLine().ToUpper();
        }
    }
}

Answer 1

从OR更改为AND逻辑运算符：

(response != "Y") && (response != "N")

Answer 2

((response != "Y") || (response != "N"))始终为true

Answer 3

while ((response != "Y") || (response != "N"))

永远是真的，因为响应不能同时是Y和N.

Answer 4

确定。如果while循环终止怎么办？我们希望它再次检查：

public void checkResponse(string response, string confirmValue)
{
Check:
    Console.WriteLine(response);
    Console.WriteLine(response);
    if (response == "Y")
    {
        return;
    }
    else if (response == "N")
    {
        Environment.Exit(0);
    }
    else
    {
        while ((response != "Y") && (response != "N"))
        {
            Console.Clear();
            Console.WriteLine("\"" + response + "\" is not a valid response.");
            Console.WriteLine();
            Console.WriteLine("You entered:" + confirmValue);
            Console.WriteLine("Is this correct? (Y/N)");
            response = Console.ReadLine().ToUpper();
        }
        goto Check;
    }
}

或者，更好：

public void checkResponse(string response, string confirmValue)
{
    Console.WriteLine(response);
    while (response != "Y" && response != "N")
    {
            Console.Clear();
            Console.WriteLine("\"" + response + "\" is not a valid response.");
            Console.WriteLine();
            Console.WriteLine("You entered:" + confirmValue);
            Console.WriteLine("Is this correct? (Y/N)");
            response = Console.ReadLine().ToUpper();
    }
    if (response == "N")
           Environment.Exit(0);
}

Answer 5

你确定输入也是大写的吗？您可以使用equals方法并忽略大小写。

message.Equals("Y", StringComparison.InvariantCultureIgnoreCase);

编辑：虽然这可能更好地用于或代替一个错误，并且是您的实际问题。

而声明忽略响应值

5 个答案: