java - 在程序中添加 for 循环时遇到问题

Question

在我的旧程序中添加 for 循环时遇到问题。我必须这样做，所以最后用户可以选择再次提问。这就是我到目前为止所拥有的也刚刚开始学习循环，如果问题很愚蠢，对不起

http://gyazo.com/a71e2a0b06ed41c47d62ccc05d8ffec8

Answer 1

你的问题并不愚蠢，我认为你只是在这里有错误的想法。

无论如何，这是您的代码，可编辑和可复制

import java.util.Scanner;

public class DogYears
{

   public static void main(String[] args)
   {

      Scanner scan = new Scanner(System.in);
      System.out.println("Enter your dog's age in human years: ");
      int age = scan.nextInt();
      int dogAge = age * 7;
      System.out.println("Your dog is " + age + " in human years and " + dogAge 
         + " in dog years!");
   //       scan.close();   <--- don't close it, you want to be able to do it again, right??
      if(dogAge>=150)
      {

         System.out.println("Likely story");

      }

      else if(dogAge>=80 && dogAge<150)
      {

         System.out.println("Hello grand-dog");

      }

      else if(dogAge>=40 && dogAge<80)
      {

         System.out.println("Boring!");

      }

      else if(dogAge>=20 && dogAge<40)
      {

         System.out.println("Get a job!");

      }

      else if(dogAge<20)
      {

         System.out.println("Just a pup!");

      }

   }

}

/* 

this is the code you had trouble including

for(int age = scan.nextInt(); int dogAge = age * 7; i++);
{

System.out.print("Enter your dog's age in human years: ");

}

 */

无论如何，这就是你的代码。您需要做的就是复制粘贴，然后突出显示所有代码，然后按文本字段上方小框中的 2 个括号符号。

现在，对于您的实际问题，使这一切成为可能的一种简单方法是，将 for 循环围绕您希望程序重复的所有内容（以及我添加的一种方法以确保它是数字的），这就是我的意思.

    import java.util.Scanner;

public class DogYears
{

   public static void main(String[] args)
   {

      Scanner scan = new Scanner(System.in);

      System.out.println("Enter your dog's age in human years. ");

      int age = scan.nextInt();

      for(int i = 0; i < 10000; i++)
      {



         int dogAge = age * 7;
         System.out.println("Your dog is " + age + " in human years and " + dogAge 
            + " in dog years!");

      //       scan.close();   <--- don't close it, you want to be able to do it again, right??

         if(dogAge>=150)
         {

            System.out.println("Likely story");

         }

         else if(dogAge>=80 && dogAge<150)
         {

            System.out.println("Hello grand-dog");

         }

         else if(dogAge>=40 && dogAge<80)
         {

            System.out.println("Boring!");

         }

         else if(dogAge>=20 && dogAge<40)
         {

            System.out.println("Get a job!");

         }

         else if(dogAge<20)
         {

            System.out.println("Just a pup!");

         }

         System.out.print("Enter your dog's age in human years. (Enter a negative number to stop the program)\n");

         String response = scan.next();

         age = Integer.parseInt(response);

         if(age < 0)
         {

            i = 10001;

         }




      }

   }


}