If statement 需要使用JOptionPane和if/if-else提供多个答案

创建一个简单的教学计划，我就陷入了（我认为是）收尾阶段

问题是，我不知道如何计算“小时”变量，使其在声明后始终保持不变

这是我使用Java的第一年，请原谅我的糟糕风格

import java.util.*;
import javax.swing.JOptionPane;

/**
The application calculates the cost of tuition for one semester at OCC.
*/

public class TuitionOCC
   {
public static void main(String[] args)
   {

   String input; 
   int residency;
   byte credits;
   int residentTuition;
   int nonTuition;
   int internationalTuition;
   int hours;
   double tuition;


   residentTuition = 82;
   nonTuition = 154;
   internationalTuition = 216;


     JOptionPane.showMessageDialog(null, "Calculate your tuition!",        "Tuition",JOptionPane.INFORMATION_MESSAGE);

    input = JOptionPane.showInputDialog("Are you a:\n" +
    "1- College District Resident\n" +
    "2- Non-Resident of College District\n" +
    "3- Out-of-State or International Student");             

     residency = Integer.parseInt(input);

     if (residency == 1)
    {


     input = JOptionPane.showInputDialog("How many credit hours are you taking?: ");

     hours = Integer.parseInt(input);
    if (hours <=0)
     JOptionPane.showMessageDialog(null,"You must enter a value of 1 or more.\n" + "Please run the program again", "Error", JOptionPane.ERROR_MESSAGE);
 } 

 else if (residency == 2)
 {

 residency = nonTuition;

  input = JOptionPane.showInputDialog("How many credit hours are you taking?: ");

     hours = Integer.parseInt(input);
  if (hours <=0)
     JOptionPane.showMessageDialog(null,"You must enter a value of 1 or more.\n" + "Please run the program again", "Error", JOptionPane.ERROR_MESSAGE);
 }
 else if (residency == 3)
 {

 residency = internationalTuition;

 input = JOptionPane.showInputDialog("How many credit hours are you taking?: ");

     hours = Integer.parseInt(input);
  if (hours <=0)
     JOptionPane.showMessageDialog(null,"You must enter a value of 1 or more.\n" + "Please run the program again", "Error", JOptionPane.ERROR_MESSAGE);
 }


else
      {
         JOptionPane.showMessageDialog(null, "You must enter a 1, 2, or 3\n" + "Please run the program again", "Error", JOptionPane.ERROR_MESSAGE);
            System.exit(0);
   }


tuition = hours * residency; 


if 
   (residency == 1)
   {  
         JOptionPane.showMessageDialog(null, hours + " hours at $ " + residentTuition + "per hour yields a tuition of " + tuition);
   }

else if 
   (residency == 2)
   {  
         JOptionPane.showMessageDialog(null, hours + " hours at $ " + nonTuition + "per hour yields a tuition of " + tuition);
   }

else if 
   (residency == 3)
   {  
         JOptionPane.showMessageDialog(null, hours + " hours at $ " + internationalTuition + "per hour yields a tuition of " + tuition);
   }



      }



}

import java.util.*；
导入javax.swing.JOptionPane；
/**
该应用程序计算OCC一学期的学费。
*/
公共课学费
{
公共静态void main（字符串[]args）
{
字符串输入；
国际居住；
字节信用；
国际学生公寓学费；
int非图腾；
国际学费；
整小时；
双倍学费；
剩余学费=82；
非图腾=154；
国际学费=216；
showMessageDialog（null，“计算学费！”，“学费”，JOptionPane.INFORMATION\u消息）；
input=JOptionPane.showInputDialog（“您是：\n”+
“1-学院区居民\n”+
“2-大学区的非居民\n”+
“3-国外或国际学生”）；
常驻=整数.parseInt（输入）；
如果（居住时间==1）
{
input=JOptionPane.showInputDialog（“你修了多少学时？”：”；
小时=整数.parseInt（输入）；
如果（hours如果要使小时数恒定，则可以执行以下操作：

input = JOptionPane.showInputDialog("How many credit hours are you taking?: ");
final hours = Integer.parseInt(input);

您还可以将JOptionPane放在if语句的顶部，这样您就不会在if语句的每个块上重新分配值。
同样，您可以对代码执行此操作以缩短所有内容

import java.util.*;
import javax.swing.JOptionPane;

/**
The application calculates the cost of tuition for one semester at OCC.
*/

public class TuitionOCC {
    public static void main (String[] args) {

        String input;
        int residency;
        byte credits;
        int residentTuition;
        int nonTuition;
        int internationalTuition;
        double tuition;


        residentTuition = 82;
        nonTuition = 154;
        internationalTuition = 216;


        JOptionPane.showMessageDialog(null, "Calculate your tuition!",        "Tuition",JOptionPane.INFORMATION_MESSAGE);

        input = JOptionPane.showInputDialog("Are you a:\n" +
        "1- College District Resident\n" +
        "2- Non-Resident of College District\n" +
        "3- Out-of-State or International Student");         

        residency = Integer.parseInt(input);

        input = JOptionPane.showInputDialog("How many credit hours are you taking?: ");
        final int hours = Integer.parseInt(input);

        if (hours <= 0) {
            JOptionPane.showMessageDialog(null,"You must enter a value of 1 or more.\n" + "Please run the program again", "Error", JOptionPane.ERROR_MESSAGE);
        }
        else {
            tuition = hours * residency; 
            if (residency == 1) {
                JOptionPane.showMessageDialog(null, hours + " hours at $ " + residentTuition + "per hour yields a tuition of " + tuition);
            } else if (residency == 2) {
                JOptionPane.showMessageDialog(null, hours + " hours at $ " + nonTuition + "per hour yields a tuition of " + tuition);
            } else if (residency == 3) {
                JOptionPane.showMessageDialog(null, hours + " hours at $ " + internationalTuition + "per hour yields a tuition of " + tuition);
            } else {
                JOptionPane.showMessageDialog(null, "You must enter a 1, 2, or 3\n" + "Please run the program again", "Error", JOptionPane.ERROR_MESSAGE);
                System.exit(0);
            }
        }
    }
}

import java.util.*；
导入javax.swing.JOptionPane；
/**
该应用程序计算OCC一学期的学费。
*/
公共课学费{
公共静态void main（字符串[]args）{
字符串输入；
国际居住；
字节信用；
国际学生公寓学费；
int非图腾；
国际学费；
双倍学费；
剩余学费=82；
非图腾=154；
国际学费=216；
showMessageDialog（null，“计算学费！”，“学费”，JOptionPane.INFORMATION\u消息）；
input=JOptionPane.showInputDialog（“您是：\n”+
“1-学院区居民\n”+
“2-大学区的非居民\n”+
“3-国外或国际学生”）；
常驻=整数.parseInt（输入）；
input=JOptionPane.showInputDialog（“你修了多少学时？”：”；
最终整数小时数=整数.parseInt（输入）；
如果（小时）