Help with Java work.

**sickwookie** · 10-16-09, 09:28 AM

Originally Posted by Imisnew2

Lol, the irony - My next C++ project (a snipped from it anyway)

Originally Posted by Professor

For example, the postfix expression 5 6 7 8 + - * 9 - evaluates as follows
• First apply + to 7 8 yielding 15. The new expression is 5 6 15 - * 9 -.
• Next apply - to 6 15 yielding -9. The new expression is 5 -9 * 9 -.
• Third, apply the * to 5 and -9 yielding -45. The new expression is -45 9 -.
• Last apply the final - to -45 and 9 to get -54. This is the result.

I remember that assignment. If I recall it was an exercise in using stacks. Push values onto the stack until you hit an operator pop two values apply operator and push result until you are done.

Kinda makes me miss school. If only real world programming problems were this much fun.

**Ewok** · 10-16-09, 09:38 AM

Originally Posted by sickwookie

Kinda makes me miss school. If only real world programming problems were this much fun.

They can be. Go find yourself a project. That's half the reason I work on lonestar, its a fun "real world" programming problem.

**sickwookie** · 10-16-09, 10:08 AM

Originally Posted by Ewok

Originally Posted by sickwookie

Kinda makes me miss school. If only real world programming problems were this much fun.

They can be. Go find yourself a project. That's half the reason I work on lonestar, its a fun "real world" programming problem.

Well, I was referring to the fact that in the "real world" the programming is the easy part. Dealing with management and anyone with a PHD is the real pain in my ass.

I may check out the lonestar code just for shits though.

**Ewok** · 10-16-09, 03:43 PM

Feel free, SoccerDog is starting to experiment with it, and I could use any kind of help. Even for simple things or just polishing features up.

Although here, management is BD and the other highs, so... yeah. jk

.. I think BD even has a PHD...

**mpgorans** · 10-16-09, 11:18 PM

I'm having trouble getting the min and max value. They come out as the same value.

Code:

       
import java.util.Scanner;
public class Calc
{
  public static void main (String&#91;] args)
  {
   Scanner scan = new Scanner(System.in);

   final int SENTINEL = -999;
   final Boolean DEBUG = false;
   final char OPERATOR1 = '+', OPERATOR2 = '-',
         OPERATOR3 = '*', OPERATOR4 = '/';
   int numLines = 0;
   int min = 0;
   int max = 0;
   int num1 = 0;
   int num2 = 0;
   int result = 0;
   char math;

   if(scan.hasNextInt())
   {
     num1 = scan.nextInt();
   }
   else
   {
     System.out.println("Error: Input is not an integer.");
     System.exit(0);
   }

   System.out.println("==================");
   System.out.println("Simple calculator");
   System.out.println("==================");
     while(num1 != SENTINEL)
     {
     math = scan.next().charAt(0);
     if(scan.hasNextInt())
     {
      num2 = scan.nextInt();
     }
     else
     {
      System.out.println("Error: Input is not an integer.");
      System.exit(0);
     }

     if(math == OPERATOR1)
     {
      result = num1 + num2;
     }
     if(math == OPERATOR2)
     {
      result = num1 - num2;
     }
     if(math == OPERATOR3)
     {
      result = num1 * num2;
     }
     if(math == OPERATOR4)
     {
      if(num2 == 0)
      {
        System.out.println("Error: Cannot devide by 0");
        System.exit(0);
      }
      else
      {
        result = num1 / num2;
      }
     }

     if(math != OPERATOR1 && math != OPERATOR2 && math != OPERATOR3 &&
      math != OPERATOR4)
 
        {
      System.out.println("Error: Operator is invalid.");
      System.exit(0);
     }

     System.out.println("Operation: " + num1 + " " + math + " " + num2);
     System.out.println("Result  " + ": " + result);
     System.out.println();

     if(result >= max)
     {
      result = max;
     }
     if(result <= min)
     {
      result = min;
     }
     numLines++;

     if(DEBUG)
     {
      System.out.println("Debug Information:");
      System.out.println("  Number of lines read = " + numLines);
      System.out.println("  Current max: " + max);
      System.out.println("  Current min: " + min);
     }

     if(scan.hasNextInt())
     {
      num1 = scan.nextInt();
     }
     else
     {
      System.out.println("Error: Input is not an integer.");
      System.exit(0);
     }
   }
   System.out.println("Number of lines read: " + numLines);
   System.out.println("Maximum calculated value: " + max);
   System.out.println("Minimum calculated value: " + min);
  }
}

**i8pptuakamonstercam** · 10-17-09, 12:13 AM

In this assignment you must initialize max and min to the result of
the first valid calculation; a request for division by zero
is not valid. To do this you will need to use an "if" statement
in order to initialize max and min to the calculated value
when they have not yet been initialized and when division by zero
is not being requested.

example)

if (Input your boolean statement here)
{
iMin = result;
iMax = result;
}

so first things, for your max and min take off your '= 0'. They will be initialized to the FIRST VALID RESULT