Question

我有以下代码。当我在控制台中键入0时，我希望控制台显示＆＃34;请重新输入您的年龄＆＃34;但是永远不会输入if块并退出程序。我做错了什么？

Console.WriteLine("Please entre your first name:");
            Console.ReadLine();
            Console.WriteLine("Please enter your last name:");
            Console.ReadLine();
            Console.WriteLine("Please type your age:");
            Console.ReadLine();

            int minAge = 18;
            int maxAge = 68;

            if (minAge < 18)
               if (maxAge > 68)

                Console.WriteLine("Please re-enter your age");
            else
                Console.WriteLine("Please choose f for female or m for male:");

Answer 1

您没有将用户输入读入age变量。执行此操作时，您需要考虑用户可能键入的非数字字符。您也没有将if / else块包裹在花括号内，导致逻辑流程与您的意图不符。

以下代码将控制台输入读入年龄变量，使用int.TryParse拒绝不可解析的输入，并将minAge和maxAge值保留为constants。我们保留looping，直到用户输入有效数字作为年龄，如果他们没有资格继续，因为他们太年轻或太老，我们会退出：

const int minAge = 18;
const int maxAge = 68;
int age;

do
{
    Console.WriteLine("Please type your age:");
} while (!int.TryParse(Console.ReadLine(), out age));

if (age < minAge || age > maxAge)
{
    Console.WriteLine("I'm sorry, this application is for people aged {0} to {1} only", minAge, maxAge);
    return; // or exit console app
}

Console.WriteLine("Please choose f for female or m for male:");

Answer 2

您没有存储输入的年龄。因此，程序永远不会到达下一部分，因为您将minAge与minAge和maxAge与maxAge进行比较。也许你可以使用

int age = Convert.ToInt32(Console.Readline())

编辑：如果您不想要任何例外，可以使用

处理

int age;
bool res = Int32.TryParse(Console.Readline(), out age);
if (!res)
     Console.WriteLine("Please re-enter your age");

然后在下一部分中使用它们

 if (age < minAge || age > maxAge )
      Console.WriteLine("Please re-enter your age");
 else
      Console.WriteLine("Please choose f for female or m for male:");

Answer 3

尝试以下可能会有所帮助，

        int userage;
        Console.WriteLine("Please type your age:");
        userage=int.Parse(Console.ReadLine());

        int minAge = 18;
        int maxAge = 68;

        if (userage>minAge || userage<maxAge)
                Console.WriteLine("Age is not accepted");
            else
            Console.WriteLine("Your Age is {0}",userage.ToString());
            //do what ever you want
            //Console.WriteLine("Please choose f for female or m for male:");
        Console.ReadLine();

不输入if / else块

3 个答案: