C＃读取整数输入

Question

我想要一些关于用户整数输入的快速帮助。如果我使用字符串我没有问题，但当我尝试将其转换为int数时，程序崩溃。任何快速修复？

string a = Console.ReadLine();
int age = Convert.ToInt32(a);
Console.WriteLine("What is your age?" + age);

if ((age >= 1) && (age <= 6))
{
    Console.WriteLine("you are in Preschool");
}
else if ((age == 7) && (age >= 13))
{
    Console.WriteLine("you are in Elementary School");
}
else if ((age == 14) && (age >= 18))
{
    Console.WriteLine("You are in High School");
}
else if ((age == 19) && (age >= 26))
{
    Console.WriteLine("You are probably in College");
}
else
{
    Console.WriteLine("you probaby have graduated already");
}

Answer 1

您的代码中的第一个更改应该是正确解析整数值

 int age = -1;
 if(int.TryParse(a,out age))
 {
   //rest of code 
 }

（适用问题） 其他变化是你的条件

 else if ((age == 7) && (age >= 13))

这不会像您进行&&操作一样有效，并说age==7 && age>=13 这意味着年龄必须是7岁，必须大于13岁

适用于所有条件

  else if ((age == 7) && (age >= 13))
    {
        Console.WriteLine("you are in Elementary School");
    }
    else if ((age == 14) && (age >= 18))
    {
        Console.WriteLine("You are in High School");
    }
    else if ((age == 19) && (age >= 26))
    {
        Console.WriteLine("You are probably in College");
    }

似乎应该（解决方案）

   else if ((age >= 7) && (age <= 13))
    {
        Console.WriteLine("you are in Elementary School");
    }
    else if ((age >= 14) && (age <= 18))
    {
        Console.WriteLine("You are in High School");
    }
    else if ((age >= 19) && (age <= 26))
    {
        Console.WriteLine("You are probably in College");
    }

完整的解决方案是

 Console.WriteLine("What is your age?");
 string a = Console.ReadLine();
 int age = -1;
 if(int.TryParse(a,out age))
 {
    Console.WriteLine("your age is : " + age);

    if(age < 1)
    {
       Console.WriteLine("Input value should be greater then 0");
    }
    else if ((age >= 1) && (age <= 6))
    {
        Console.WriteLine("you are in Preschool");
    }
    else if ((age >= 7) && (age <= 13))
    {
        Console.WriteLine("you are in Elementary School");
    }
    else if ((age >= 14) && (age <= 18))
    {
        Console.WriteLine("You are in High School");
    }
    else if ((age >= 19) && (age <= 26))
    {
        Console.WriteLine("You are probably in College");
    }
    else
    {
        Console.WriteLine("you probaby have graduated already");
    }
 }
 else 
 {
      Console.WriteLine("InCorrect input value");
 }

Answer 2

解决问题的另一种方法是使用少量代码。对我来说，如果不那么复杂的if语句会更容易阅读。由于年龄间隔，Switch语句对这种情况没有帮助。它只会变得更复杂。

string text = String.Empty;
int age;
Console.WriteLine("What is your age?");

if (int.TryParse(Console.ReadLine(), out age))
  {
    if (age > 26)
      text = "You probaby have graduated already.";
    else if (age < 1)
      text = "You probaby not started Preschool.";
    else if (age < 7)
      text = "You are in Preschool.";
    else if (age < 14)
      text = "You are in Elementary School.";
    else if (age < 19)
      text = "You are in High School.";
    else
      text = "You are probably in College.";
    Console.WriteLine(text);
  }
}

Answer 3

试试这个： - 如果条件为false，请将其更改为如下所示。

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