Math Drill

**Java Neil** · February 2nd, 2011, 11:39 PM

Hello fellow programers...I hope someone can help me. I'm new to java and I have an assignment for extra credit that I could really use. This is my first programing course and this problem has me a bit out of my league.

Anyway the assignment is "Create math drill program that asks category (+,-,/,*), gives 10 random questions, keeps score, time elapsed, and then asks if you want to do it again. 20 points. For an extra 5 points, include modulus."

So far, this is my code...

    import javax.swing.JOptionPane;
 
  public class MathDrillLoop {//start program
  public static void main (String[] args) {//start main
 
      //Create start time
      long startTime = System.currentTimeMillis();
      //declare string output
      String output = "";
 
 
      //declare Number of questions
      final int NUMBER_OF_QUESTIONS = 10;
      int score = 0;
      for (int count = 0; count < 10; count++) {
      JOptionPane.showMessageDialog(null,"Correct count is " + count);
 
 
      //declare integers
      int number1, number2, answer, temp;
    }
      //declare strings
      String str1, str2, answerString, replyString;
 
      do{
      //Ask user to choose problem type
      String entercodeString = JOptionPane.showInputDialog(
      "Choose 1 for addition, 2 for subtraction, 3 for multiplication, 4 for division, or 5 for modulo ");
      while (! entercode = ("1")&&
	   entercodeString!= ("2") &&
	   entercodeString != ("3") &&
	   entercodeString != ("4") &&
	   entercodeString != ("5"));
	 {
 
      output = "Invalid problem type, Try again ";
      JOptionPane.showMessageDialog(null,output);
 
      int opcode = Integer.parseInt(entercodeString);
 
     //Switch statements
      switch (opcode) {
     //if addition enter first number
      case (1) : str1 = JOptionPane.showInputDialog(
      "Enter integer value, for example 5:");
       number1 = Integer.parseInt(str1);
 
     //Enter second number
       str2 = JOptionPane.showInputDialog(
       "Enter integer value, for example 7:");
       number2 = Integer.parseInt(str2);
 
       answerString = JOptionPane.showInputDialog
       ("What is " + number1 + " + " + number2 + " ? ");
 
       answer = Integer.parseInt(answerString);
 
 
       if (number1 + number2 == answer){
       replyString = "Good Job";
       score++;
      }
 
       else
       replyString = "Incorrect";
       JOptionPane.showMessageDialog(null, replyString);
 
 
      //increase count by 1
       count++;
       break;
 
      //if subtaction enter first number
       case (2) : str1 = JOptionPane.showInputDialog(
       "Enter integer value, for example 5:");
       number1 = Integer.parseInt(str1);
 
      //Enter second number
       str2 = JOptionPane.showInputDialog(
       "Enter integer value, for example 7:");
       number2 = Integer.parseInt(str2);
 
       if (number1 < number2) {
       temp = number1;
       number1 = number2;
       number2 = temp;
      }
 
      answerString = JOptionPane.showInputDialog
      ("What is " + number1 + " - " + number2 + " ? ");
 
      answer = Integer.parseInt(answerString);
 
 
      if (number1 - number2 == answer){
      replyString = "Good Job";
      score++;
      }
 
      else
      replyString = "Incorrect";
      JOptionPane.showMessageDialog(null, replyString);
 
     //increase count by 1
      count++;
      break;
 
     // if multiplication enter first number
      case (3) : str1 = JOptionPane.showInputDialog(
      "Enter integer value, for example 5:");
      number1 = Integer.parseInt(str1);
 
     //Enter second number
      str2 = JOptionPane.showInputDialog(
      "Enter integer value, for example 7:");
      number2 = Integer.parseInt(str2);
 
 
      answerString = JOptionPane.showInputDialog
      ("What is " + number1 + " * " + number2 + " ? ");
 
      answer = Integer.parseInt(answerString);
 
 
      if (number1 * number2 == answer){
      replyString = "Good Job";
      score++;
      }
 
      else
      replyString = "Incorrect";
      JOptionPane.showMessageDialog(null, replyString);
 
     //increase count by 1
      count++;
      break;
 
     //if division enter first number
      case (4) : str1 = JOptionPane.showInputDialog(
      "Enter integer value, for example 5:");
      number1 = Integer.parseInt(str1);
 
     //Enter second number
      str2 = JOptionPane.showInputDialog(
      "Enter integer value, for example 7:");
      number2 = Integer.parseInt(str2);
 
      answerString = JOptionPane.showInputDialog
      ("What is " + number1 + " / " + number2 + " ? ");
 
      answer = Integer.parseInt(answerString);
 
 
      if (number1 / number2 == answer){
      replyString = "Good Job";
      score++;
     }
 
      else
      replyString = "Incorrect";
      JOptionPane.showMessageDialog(null, replyString);
 
     //increase count by 1
      count++;
      break;
 
     //if modulo enter first number
      case (5) : str1 = JOptionPane.showInputDialog(
      "Enter integer value, for example 5:");
      number1 = Integer.parseInt(str1);
 
     //Enter second number
      str2 = JOptionPane.showInputDialog(
      "Enter integer value, for example 7:");
      number2 = Integer.parseInt(str2);
 
 
      answerString = JOptionPane.showInputDialog
      ("What is " + number1 + " % " + number2 + " ? ");
 
      answer = Integer.parseInt(answerString);
 
 
      if (number1 % number2 == answer){
      replyString = "Good Job";
      score++;
     }
 
      else
      replyString = "Incorrect";
      JOptionPane.showMessageDialog(null, replyString);
 
     //increase count by 1
      count++;
      break;
 
      default : output = "Invalid problem type, Try again ";
      JOptionPane.showMessageDialog(null,output);
      System.exit(0); }
 
 
      long endTime = System.currentTimeMillis();
      long testTime = endTime - startTime;
 
      output = ("Correct count is " + count +
      "\nTest time is " + testTime / 1000 + " seconds\n" + output);
 
      input = JOptionPane.showInputDialog(null, "Do you want to take the quiz again?", "yes or no");
      if(input == "yes")
      return;
 
      if(input == "no");
      System.exit(0);
 
		}
 
	}

I hope someone can not only show me the errors I have made but also give me some pointers.

I bow down to your expertise.

Neil

**javapenguin** · February 2nd, 2011, 11:56 PM

Please use:

[highlight=java] code [/highlgiht]
It makes code easier to read.

import javax.swing.JOptionPane;
 
public class MathDrillLoop {//start program
public static void main (String[] args) {//start main
 
//Create start time
long startTime = System.currentTimeMillis();
//declare string output
String output = "";
 
 
//declare Number of questions
final int NUMBER_OF_QUESTIONS = 10;
int score = 0;
for (int count = 0; count < 10; count++) {
JOptionPane.showMessageDialog(null,"Correct count is " + count);
 
 
//declare integers
int number1, number2, answer, temp;
}
//declare strings
String str1, str2, answerString, replyString;
 
do{
//Ask user to choose problem type
String entercodeString = JOptionPane.showInputDialog(
"Choose 1 for addition, 2 for subtraction, 3 for multiplication, 4 for division, or 5 for modulo ");
while (! entercode = ("1")&&
entercodeString!= ("2") &&
entercodeString != ("3") &&
entercodeString != ("4") &&
entercodeString != ("5"));
{
 
output = "Invalid problem type, Try again ";
JOptionPane.showMessageDialog(null,output);
 
int opcode = Integer.parseInt(entercodeString);
 
//Switch statements
switch (opcode) {
//if addition enter first number
case (1) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " + " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 + number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
 
//increase count by 1
count++;
break;
 
//if subtaction enter first number
case (2) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
if (number1 < number2) {
temp = number1;
number1 = number2;
number2 = temp;
}
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " - " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 - number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
//increase count by 1
count++;
break;
 
// if multiplication enter first number
case (3) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " * " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 * number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
//increase count by 1
count++;
break;
 
//if division enter first number
case (4) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " / " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 / number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
//increase count by 1
count++;
break;
 
//if modulo enter first number
case (5) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " % " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 % number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
//increase count by 1
count++;
break;
 
default : output = "Invalid problem type, Try again ";
JOptionPane.showMessageDialog(null,output);
System.exit(0); }
 
 
long endTime = System.currentTimeMillis();
long testTime = endTime - startTime;
 
output = ("Correct count is " + count +
"\nTest time is " + testTime / 1000 + " seconds\n" + output);
 
input = JOptionPane.showInputDialog(null, "Do you want to take the quiz again?", "yes or no");
if(input == "yes")
return;
 
if(input == "no");
System.exit(0);
 
}
 
}

What errors are you getting?

**javapenguin** · February 2nd, 2011, 11:57 PM

while (! entercode = ("1")&&
entercodeString!= ("2") &&
entercodeString != ("3") &&
entercodeString != ("4") &&
entercodeString != ("5"));

Also, I think with Strings and other Objects, you use .equals(), not == or the stuff used for primitive types.

And it might be better if you had some number to exit the do....while loop. If you had some number entered that would exit the program, you could just use a bunch of if...else if...else statments
inside the do...while loop.

I'm not sure what you are incrementing with count.

parseInt the input String above and perhaps have an option that asks to exit.
However...to do this you'll need to create and initialize another int variable called choice.

 
int valueEntered = 0;
int choice = 0;
while (valueEntered!=6 || choice !=JOptionPane.YES_OPTION)
{
String enteredByUser = JOptionPane.showInputDialog(null, "Choose 1 for addition, 2 for subtraction, 3 for multiplication, 4 for division, or 5 for modulo ", "Make a choice", JOptionPane.PLAIN_MESSAGE);
valueEntered = Integer.parseInt(enteredByUser);
 
// a bunch of if and else if and else statements that will be defined according to what you had in your code to do when those options were selected
 
// if choice = 6, go to dialog window shown below.
// if choice is not any of them...say "Error" or something like that,  and...if set up right...it'll just ask again.  
}

For how to make the JOptionPane window ask you or no, use this site for reference:

How to Make Dialogs (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Swing Components)
And here might help too:
http://download.oracle.com/javase/tu...ialogDemo.java
Just do something like:

if (choice == JOptionPane.YES_OPTION)
{
System.exit(0);
}
 
else 
{
// don't do anything
}

Also, it appears you're defining some values inside that for loop. Define them before it or else they'll go out of scope when it ends.

**Java Neil** · February 3rd, 2011, 07:27 AM

Originally Posted by javapenguin

Please use:

[highlight=java] code [/highlgiht]
It makes code easier to read.

import javax.swing.JOptionPane;
 
public class MathDrillLoop {//start program
public static void main (String[] args) {//start main
 
//Create start time
long startTime = System.currentTimeMillis();
//declare string output
String output = "";
 
 
//declare Number of questions
final int NUMBER_OF_QUESTIONS = 10;
int score = 0;
for (int count = 0; count < 10; count++) {
JOptionPane.showMessageDialog(null,"Correct count is " + count);
 
 
//declare integers
int number1, number2, answer, temp;
}
//declare strings
String str1, str2, answerString, replyString;
 
do{
//Ask user to choose problem type
String entercodeString = JOptionPane.showInputDialog(
"Choose 1 for addition, 2 for subtraction, 3 for multiplication, 4 for division, or 5 for modulo ");
while (! entercode = ("1")&&
entercodeString!= ("2") &&
entercodeString != ("3") &&
entercodeString != ("4") &&
entercodeString != ("5"));
{
 
output = "Invalid problem type, Try again ";
JOptionPane.showMessageDialog(null,output);
 
int opcode = Integer.parseInt(entercodeString);
 
//Switch statements
switch (opcode) {
//if addition enter first number
case (1) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " + " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 + number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
 
//increase count by 1
count++;
break;
 
//if subtaction enter first number
case (2) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
if (number1 < number2) {
temp = number1;
number1 = number2;
number2 = temp;
}
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " - " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 - number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
//increase count by 1
count++;
break;
 
// if multiplication enter first number
case (3) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " * " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 * number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
//increase count by 1
count++;
break;
 
//if division enter first number
case (4) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " / " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 / number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
//increase count by 1
count++;
break;
 
//if modulo enter first number
case (5) : str1 = JOptionPane.showInputDialog(
"Enter integer value, for example 5:");
number1 = Integer.parseInt(str1);
 
//Enter second number
str2 = JOptionPane.showInputDialog(
"Enter integer value, for example 7:");
number2 = Integer.parseInt(str2);
 
 
answerString = JOptionPane.showInputDialog
("What is " + number1 + " % " + number2 + " ? ");
 
answer = Integer.parseInt(answerString);
 
 
if (number1 % number2 == answer){
replyString = "Good Job";
score++;
}
 
else
replyString = "Incorrect";
JOptionPane.showMessageDialog(null, replyString);
 
//increase count by 1
count++;
break;
 
default : output = "Invalid problem type, Try again ";
JOptionPane.showMessageDialog(null,output);
System.exit(0); }
 
 
long endTime = System.currentTimeMillis();
long testTime = endTime - startTime;
 
output = ("Correct count is " + count +
"\nTest time is " + testTime / 1000 + " seconds\n" + output);
 
input = JOptionPane.showInputDialog(null, "Do you want to take the quiz again?", "yes or no");
if(input == "yes")
return;
 
if(input == "no");
System.exit(0);
 
}
 
}

What errors are you getting?

The code will not compile. It says..." reached end of file while parsing"

By the way, thanks a lot for helping me out. My teacher speaks broken English, and most of the time I can't understand him!

**newbie** · February 3rd, 2011, 02:30 PM

Firstly, welcome to the forums.
The reality is that your code is filled with logical and syntactical errors and you will have a lot of reading ahead of you.

Reached end of file while parsing usually entails a missing brace, where you have opened a curly brace but failed to close it.
If you declare variables inside a for-loop, the scope/lifetime of that variable is only going to be inside that loop.
Do...while code should be executed inside the bracers after do and is therefore different to a while loop.
Like javaPenguin said, to compare String equality, you should use .equals() or .equalsIgnoreCase() and not == or !=, otherwise you are just checking to see if the two Strings share the same memory reference.

Suggested Reading (Links):

**Java Neil** · February 3rd, 2011, 09:39 PM

Thanks for the tips everyone. I have a working code kinda. There are still some logical bugs to fix. At the end of the program I am supposed to give the user a chance to either start over or quit. Right now it is not going to the top of the program but it's show the score from the last run.

Here is the new code. Any help would be great!

   import javax.swing.JOptionPane;
   public class MathDrill{
      public static void main(String[] args){
         final int NUMBER_OF_QUESTIONS = 10;
         int correctCount = 0;
         int count = 0;
         long startTime = System.currentTimeMillis();
         String output ="";
         int option = 0;
 
         do{
 
            JOptionPane.showMessageDialog(null, "Welcome to Neil's Math Drill");                      
 
            int operator = 0;              
 
            //prompt user to enter a math operator for test
            String operatorString = JOptionPane.showInputDialog(null, "<html><u><i><b>Please enter operation</b></i></u></html>"
               + "\nFor addition problems enter (1)" + "\nFor subtraction problems enter (2)" +
               "\nFor multiplication problems enter (3)" + "\nFor division problems enter (4)" +
               "\nFor modulo problems enter (5)");
            operator = Integer.parseInt(operatorString);
 
            while(count < NUMBER_OF_QUESTIONS){
               int timesleft = (NUMBER_OF_QUESTIONS - count);
               JOptionPane.showMessageDialog(null, "Question number  "
                  + (NUMBER_OF_QUESTIONS - count));
 
            	//generate two integers
               int num1 = (int)(Math.random() * 10);
               int num2 = (int)(Math.random() * 10); 
 
                  if (num1 < num2){
                     int temp = num1;
                     num1 = num2;
                     num2 = temp;
                  }
 
 
               while ((operator < 1) || (operator > 5)){
 
                  char symbol;
                  switch (operator){
 
                     case 1: symbol = '+';
                        break;
                     case 2: symbol = '-';
                        break;
                     case 3: symbol = '*';
                        break;
                     case 4: symbol = '/';
                        break;
                     case 5: symbol = '%';
                        break;
                  }
                  if ((operator < 1)||(operator > 5)){
                     JOptionPane.showMessageDialog(null, "Please reenter number between 1 and 5");
                  }
               }
 
 
 
               if (operator == 1){
                  String answerString = JOptionPane.showInputDialog(null, " What is " + num1 +
                     " + " + num2 + "?");
                  int answer = Integer.parseInt(answerString);
 
               //grade results
                  if (num1 + num2 == answer){
                     JOptionPane.showMessageDialog(null, "You are Correct");
                     correctCount++;
                  }
                  else
                     JOptionPane.showMessageDialog(null, "You are Incorrect\nYour answer should be "
                        + num1 + " + " + num2 + " = " + (num1 + num2));
 
                  output += "\n" + num1 + " + " + num2 + " = " + answer +
                     ((num1 + num2 == answer) ? " correct" : " wrong");
               }      
               if (operator == 2){
                  String answerString = JOptionPane.showInputDialog(null, " What is " + num1 +
                     " - " + num2 + " ? ");
                  int answer = Integer.parseInt(answerString);
 
               //grade results
                  if (num1 - num2 == answer){
                     JOptionPane.showMessageDialog(null, "You are Correct");
                     correctCount++;
                  }
                  else
                     JOptionPane.showMessageDialog(null, "You are Incorrect\nYour answer should be "
                        + num1 + " - " + num2 + " = " + (num1 - num2));
 
                  output += "\n" + num1 + " - " + num2 + " = " + answer +
                     ((num1 - num2 == answer) ? " correct" : " wrong");
               }      
               if (operator == 3){
                  String answerString = JOptionPane.showInputDialog(null, " What is " + num1 +
                     " * " + num2 + " ? ");
                  int answer = Integer.parseInt(answerString);
 
               //grade results
                  if (num1 * num2 == answer){
                     JOptionPane.showMessageDialog(null, " You are Correct");
                     correctCount++;
                  }
                  else
                     JOptionPane.showMessageDialog(null, "You are Incorrect\nYour answer should be "
                        + num1 + " * " + num2 + " = " + (num1 * num2));
 
                  output += "\n" + num1 + " * " + num2 + " = " + answer +
                     ((num1 * num2 == answer) ? " correct" : " wrong");
               }      
               if (operator == 4){
                  String answerString = JOptionPane.showInputDialog(null, " What is " + num1 +
                     " / " + num2 + " ? ");
                  int answer = Integer.parseInt(answerString);
 
               //grade results
                  if (num1 / num2 == answer){
                     JOptionPane.showMessageDialog(null, " You are Correct");
                     correctCount++;
                  }
                  else
                     JOptionPane.showMessageDialog(null, "You are Incorrect\nYour answer should be "
                        + num1 + " / " + num2 + " = " + (num1 / num2));
 
                  output += "\n" + num1 + " / " + num2 + " = " + answer +
                     ((num1 / num2 == answer) ? " correct" : " wrong");
               }      
               if (operator == 5){
                  String answerString = JOptionPane.showInputDialog(null, " What is " + num1 +
                     " % " + num2 + " ? ");
                  int answer = Integer.parseInt(answerString);
 
               //grade results
                  if (num1 % num2 == answer){
                     JOptionPane.showMessageDialog(null," You are Correct ");
                     correctCount++;
                  }
                  else
                     JOptionPane.showMessageDialog(null, "You are Incorrect\nYour answer should be "
                        + num1 + " % " + num2 + " = " + (num1 % num2));
 
                  output += "\n" + num1 + " % " + num2 + " = " + answer +
                     ((num1 % num2 == answer) ? " correct" : " wrong");
               }
               count++;
            }
 
 
            long endTime = System.currentTimeMillis();
            long testTime = (endTime - startTime);
 
            JOptionPane.showMessageDialog(null, " Correct answers = " + correctCount +
               "\nYour test took " + testTime /1000 + " seconds\n " + output);
 
 
            option = JOptionPane.showConfirmDialog(null, "Do you want to play again?");
 
         }while(option == JOptionPane.YES_OPTION);
         System.exit(0);
 
      }
 
   }

**Java Neil** · February 3rd, 2011, 10:46 PM

OK, so I've got a working program now. All I need to figure out is what to do when the random numbers generate a (zero/0) during division and modulo problems. I keep getting errors when that happens. I don't think my teacher would say anything about it but I'm here to learn as much as I can!

The error reads "Exception in thread "main" java.lang.ArithmeticException: / by zero"

Once again thanks for everyone's help, and well wishes. I think I will be spending a lot of time here and hopefully learn enough to help others as well.

**javapenguin** · February 3rd, 2011, 11:32 PM

int x = 0;
int y = 0;
 
if (choice = divide)
{
// input int 1 like normal
boolean secondValueIsZero = true;
 
while (secondValueIsZero==true)
{
try
{
 
// ask for int2  value;
secondValueIsZero = false;
}
 
catch (ArithmeticException aeRef)
{
JOptionPane.showMessageDialog(null, "Cannot divide by zero!" , "Error: / 0 ", JOptionPane.ERROR_MESSAGE);
}
}

The try block checks too see if that exception will occur. If it does, the catch block causes that message to pop up.
If it doesn't, then the while loop exists.

**Java Neil** · February 4th, 2011, 09:16 AM

Originally Posted by javapenguin

int x = 0;
int y = 0;
 
if (choice = divide)
{
// input int 1 like normal
boolean secondValueIsZero = true;
 
while (secondValueIsZero==true)
{
try
{
 
// ask for int2  value;
secondValueIsZero = false;
}
 
catch (ArithmeticException aeRef)
{
JOptionPane.showMessageDialog(null, "Cannot divide by zero!" , "Error: / 0 ", JOptionPane.ERROR_MESSAGE);
}
}

The try block checks too see if that exception will occur. If it does, the catch block causes that message to pop up.
If it doesn't, then the while loop exists.

Sorry about my ignorance, but how would I apply this method? Where would I place the code to catch the error?

**javapenguin** · February 4th, 2011, 12:23 PM

The try block looks for error. Put the thing that might cause the error in there.

The catch blocks will attempt to point out the error and display the error message.

Catching and Handling Exceptions (The Java™ Tutorials > Essential Classes > Exceptions)

**Java Neil** · February 5th, 2011, 12:34 AM

Originally Posted by javapenguin

The try block looks for error. Put the thing that might cause the error in there.

The catch blocks will attempt to point out the error and display the error message.

Catching and Handling Exceptions (The Java™ Tutorials > Essential Classes > Exceptions)

I'll give it a try and report back...Thanks for the heads up. In this case the division and the modulo statements? Right?

**Java Neil** · February 5th, 2011, 01:12 AM

After thinking about it for a while, I came up with this...

 
                if (num1 == 0)
                  num1++;
 
               if (num2 == 0)
                  num2++;

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