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我正在使用JOptionPane天左右Java程序工作。我不是在談論日期（2016年10月14日等），但天：Sunday, Monday等陣列櫃不與Java
我的問題是功能，添加特定天數的當天（例如今天是星期二然後添加5天后）。
我使用陣列訪問/指用於顯示和輸出的目的的特定一天。
我引用星期日至星期六，與分別0-6數組索引。
的問題是，假設當天是週六，如果用戶附加的3天進它的程序崩潰。
我相信這是因爲崩潰，因爲週六位於索引6和算法試圖訪問第九指數，它不存在。由於Java是一種安全的語言，它不會顯示'null'，它決定崩潰。
什麼是應該在這種情況下發生的是，從星期六，程序將顯示週二，而不是：
異常線程 「main」 java.lang.ArrayIndexOutOfBoundsException：9
我使用Netbeans作爲我的IDE，我自學java，因爲我的大學教我C++，visual basic，c＃爲我當年和課程。如果您想詳細信息，然後，
這裏的主類的源代碼：
package weekdaysprogram;
import java.util.*;
public class weekdayParametersProgramMain
{
static Scanner console = new Scanner (System.in);
public static void main(String[] args)
{
weekdayParametersProgram firstObject = new weekdayParametersProgram();
firstObject.inputMainMenu();
}
}
下面是第二類的源代碼：
package weekdaysprogram;
import javax.swing.JOptionPane;
public class weekdayParametersProgram
{
int currentDay; //variable used for referencing a certain day
String[] day = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}; //Array of days
public void inputMainMenu() //Main menu function
{
int choice;
String inputStr;
String mainMenuStr = "Day Class\n"
+ "Enter choice: \n"
+ "1. Set Day \n"
+ "2. Print Day \n"
+ "3. Print Next Day \n"
+ "4. Print Previous Day \n"
+ "5. Calculate Day \n"
+ "6. Exit";
inputStr = JOptionPane.showInputDialog(mainMenuStr);
choice = Integer.parseInt(inputStr);
switch (choice)
{
case 1:
setDay();
break;
case 2:
printDay();
break;
case 3:
printNextDay();
break;
case 4:
printPreviousDay();
break;
case 5:
calculateDay();
break;
case 6:
exit();
break;
default:
JOptionPane.showMessageDialog(null, "Error Try Again", "Error", JOptionPane.ERROR_MESSAGE);
inputMainMenu();
break;
}
}
public void calculateDay() //the 5th function I'm getting an error at aka the culprit of my error
{
String message = "Current Day: " + currentDay + " - " + day[currentDay] + "\n"
+ "Please enter the amount of days to be added: ";
int tempNum1 = currentDay;
String tempNum2 = JOptionPane.showInputDialog(message);
int tempNum3 = Integer.parseInt(tempNum2);
for (int count=0; count <= tempNum3; count++)
{
if (count == 7) tempNum1 = 0;
else if (count==0) continue; //this is a patch, since there would be a confusion if the user inputted 1 for the addtional day
else tempNum1++;
}
String nextMessage = day[currentDay] + " + " + tempNum3 + " days = " + day[tempNum1];
JOptionPane.showMessageDialog(null, nextMessage, "New Day", JOptionPane.INFORMATION_MESSAGE);
inputMainMenu();
}
public void setDay() //1st function for set day
{
String inputStr;
String message = "Enter day index: \n"
+ "0 = " + day[0] + "\n"
+ "1 = " + day[1] + "\n"
+ "2 = " + day[2] + "\n"
+ "3 = " + day[3] + "\n"
+ "4 = " + day[4] + "\n"
+ "5 = " + day[5] + "\n"
+ "6 = " + day[6] + "\n";
inputStr = JOptionPane.showInputDialog(message);
switch (inputStr)
{
case "0":
currentDay = 0;
break;
case "1":
currentDay = 1;
break;
case "2":
currentDay = 2;
break;
case "3":
currentDay = 3;
break;
case "4":
currentDay = 4;
break;
case "5":
currentDay = 5;
break;
case "6":
currentDay = 6;
break;
default:
JOptionPane.showMessageDialog(null, "Please try again.", "Error", JOptionPane.ERROR_MESSAGE);
setDay();
break;
}
inputMainMenu();
}
public void printDay() //2nd function for printing out the current day
{
JOptionPane.showMessageDialog(null, day[currentDay], "Current Day", JOptionPane.INFORMATION_MESSAGE);
inputMainMenu();
}
public void printNextDay() //3rd function for printing out the next day
{
int tempNum = currentDay;
if (tempNum == 6) tempNum = 0;
else tempNum += 1;
JOptionPane.showMessageDialog(null, day[tempNum], "Next Day", JOptionPane.INFORMATION_MESSAGE);
inputMainMenu();
}
public void printPreviousDay() //4th function for printing out the previous day
{
int tempNum = currentDay;
if (tempNum == 0) tempNum = 6;
else tempNum -= 1;
JOptionPane.showMessageDialog(null, day[tempNum], "Previous Day", JOptionPane.INFORMATION_MESSAGE);
inputMainMenu();
}
public void exit()
{
System.exit(0);
}
}
做@哈羅德另外，你可以善用你的班級名稱嗎？這在Java中是基本的東西。 – ha9u63ar