Hey Mike, I need an idea for this one

[Gabriel White]

I am supposed to write statements to declare an array of 10 Animal named myOtherPets and randomly add 10 Pig�s or Duck�s into myOtherPets
I approached it like the arraylist problem but this is just a strait up array.
This is what I have so far, but I have no idea how to fill that array.
ideas?
Thanks bro

  public static void main(String[] args)
  {
    Animal[] myOtherPets= new Animal[10];
    Random generator = new Random();
    boolean[] tracker = new boolean[10];
    int num1,count;
    count=0;
    for (int i=0; count < 10; i++)
    {
      num1 = generator.nextInt(10);
      if(tracker[num1]==false)
      {
        count++;
        tracker[num1] = true;
      }
    }
  }
}

[ April 18, 2003: Message edited by: Steve Wysocki ]

[Michael Morris]

Do you need a random aggregation of Pigs and Ducks or an equal number of each in no particular order? If the former then you would need to do something like this:

    Animal[] myOtherPets = new Animal[10];
    Random generator = new Random();
    for (int i = 0; i < myOtherPets.length; i++) {
        if (generator.nextBoolean()) {
            myOtherPets[i] = new Duck();
        } else {
            myOtherPets[i] = new Pig();
        }
    }

[Gabriel White]

I need 1 or the other, I am choosing pigs on this one.
but, I need them to say Hello, just like the last one.
All of them need to use speak("Hello")
output example
Pig0
Oink Oink: Hello
The Pig class is the same exact class as the duck class in the other example but with pigs instead of ducks
Thanks Mike

[Michael Morris]

Well, try what I posted and follow that with something like:

    int pigs = 0;
    int ducks = 0;
    for (int i = 0; i < myOtherPets.lenght; i++) {
        if (myOtherPets[i] instanceof Pig) {
            System.out.println("Pig" + pigs + " " +
                                myOtherPets[i].speak("Hello"));
            pigs++;
        } else  {
            System.out.println("Duck" + ducks + " " +
                                myOtherPets[i].speak("Hello"));
            ducks++;
        }
    }

Of course testing with instanceof may be defeating the ultimate purpose of this assignment which is to show the effects of polymorphism.

[Gabriel White]

Well this is how I put it together, Im sure Im missing something somewhere cause it bombs out with:java.lang.NullPointerException
at project9_1.Test2.main(Test2.java:20)
Pig4
Exception in thread "main"
The Pig number will every time I run it.
Thanks Mike

  public static void main(String[] args)
  {
    Animal[] myOtherPets = new Animal[10];
    int pigs = 0;
    Random generator = new Random();
    for (int i = 0; i < myOtherPets.length; i++)
    {
      if (generator.nextBoolean())
      {
        myOtherPets[i] = new Pig();
        if (myOtherPets[i] instanceof Pig) 
        {
          System.out.println("Pig" + pigs + " ");
          myOtherPets[i].speak("Hello");
          pigs++;
        }
      }
    }
  }
}

[ April 18, 2003: Message edited by: Steve Wysocki ]

[Gabriel White]

You know what Mike, I am going to make this alot more simple but it doesn't work.
it will count the pigs but it wont do the speak
it gives a null pointer exception error:
java.lang.NullPointerException
at project9_1.Test2.main(Test2.java:20)
Exception in thread "main" Pig6
This code SHOULD work. It follows num1 (the random number, but the error persists.

 public static void main(String[] args)
  {
    Animal[] myOtherPets= new Animal[10];
    Random generator = new Random();
    boolean[] tracker = new boolean[10];
    int num1, count;
    count =0;
    for (int i=0; count < myOtherPets.length; i++)
    {
      num1 = generator.nextInt(10);
      if(tracker[num1]==false)
      {
        System.out.println("Pig"+num1);
        myOtherPets[num1].speak("Hello");
        count++;
        tracker[num1] = true;
      }
    }
  }
}

[Gabriel White]

GOT IT!!
I got yours to sort of work, but I looked at your instantiated pig object and realized thats what was causing my NPE so this worked:

for (int i=0; count < myOtherPets.length; i++)
    {
      num1 = generator.nextInt(10);
      if(tracker[num1]==false)
      {
        myOtherPets[num1] = new Pig();
        System.out.print("Pig"+num1 + " ");
        myOtherPets[num1].speak("Hello");
        count++;
        tracker[num1] = true;
      }
    }

Thanks for the awesome assistance on this one Mike.
Go Spurs Go
[ April 18, 2003: Message edited by: Steve Wysocki ]

[Michael Morris]

Once again Steve, you really did this one on your own. I wimped out and went to bed and left you hangin'. I've always believed the best way to learn a programming language is to screw up and figure out why you screwed up. That is the most valuable kind of experience.

[Gabriel White]

Well, at least Im getting better at it. Your a better teacher than mine.
Anyway, you still helped a bunch, and I really appreciate it.
I'll talk to ya soon.
Cya
SW
GO SPURS GO

[Layne Lund]

Keep up the hard work. I enjoy helping you out, but as Mike says, you'll learn a lot more from your own mistakes. Keep coming back with more questions. We are glad to help point you in the right direction.
Cheers!
Layne

[Maulin Vasavada]

hi all,
my 2 cents.
also, once u know the 'wrong/bad' code, u learn to see the significance of 'better' code u know...i mean more on the code design tho..
regards
maulin