??

[foolguy]

public class Animal
{

public Animal(String aType)
{
type=new String(aType);
}

public String toString()
{
return "This is a " + type;
}

public void sound(){}



private String type;
}

//other class

public class Cat extends Animal
{
public Cat(String aName)
{
super("Cat");//call the base constructor
name=aName;
breed="Unknown";
}

public Cat(String aName, String aBreed)
{
super("Cat");
name=aName;
breed=aBreed;
}

public String toString()
{
return super.toString()+"\nIt's"+name+"the"+breed;
}

public void sound()
{
System.out.println("Miiaooww");
}

private String name;
private String breed;
}
//<the other class also same like Cat>

//main
import java.util.Random;

public class Trypoly
{
public static void main(String[] args)
{
Animal[] theAnimals={
new Dog("Rover","Poodle"),
new Cat("Max","Abyssinian"),
new Duck("Daffy","Aylesbury"),
new human("mkyong1","mkyong2")
};

Animal Choice;

Random select=new Random();

for(int i=0;i<6;i++)
{
Choice = theAnimals[select.nextInt(theAnimals.length)];

System.out.println("\nYour choice:\n"+Choice);

Choice.sound();
}
}
}

when i run , i got this message

C:\JDK1.3\MKYONG>javac Trypoly.java
Trypoly.java:24: cannot resolve symbol
symbol : method sound ()
location: class Animal
Choice.sound();
^
1 error

How do solve this <i'm a newcomer to java>
please help....

[Niklas Junel]

Since I didn't have all the classes I took the lines that tries to make an
object of dog... away. Anyway, You cant't have more than one public class
in each source-file. So I made the other classes non-public. The main-method
should exist in the public class (otherwise the system won't see the method).
As You only had the main-method in the last class, I took it away,and placed
the main-method in the Animal-class,this way I got it to work. Of course
You could have all the classes in different files, that way they can all
be public.

Niklas

import java.util.Random;
public class Animal
{

public Animal(String aType)
{
type=new String(aType);
}

public String toString()
{
return "This is a " + type;
}

public void sound(){}



private String type;

//put Your main-method in the public class

public static void main(String[] args)
{
Animal[] theAnimals={new Cat("Max","Abyssinian")};

Animal Choice;

Random select=new Random();

for(int i=0;i<6;i++)
{
Choice = theAnimals[select.nextInt(theAnimals.length)];

System.out.println("\nYour choice:\n"+Choice);

Choice.sound();
}
}
}

//other class

class Cat extends Animal
{
public Cat(String aName)
{
super("Cat");//call the base constructor
name=aName;
breed="Unknown";
}

public Cat(String aName, String aBreed)
{
super("Cat");
name=aName;
breed=aBreed;
}

public String toString()
{
return super.toString()+"\nIt's"+name+"the"+breed;
}

public void sound()
{
System.out.println("Miiaooww");
}

private String name;
private String breed;
}