Dynamically create objects at runtime - Collections?

Question

Dear Experts
During runtime i need to create several objects. Can you help me by pointing out the best practice here? Is it possible to store Man and Dog object in the single collection?
Thank you for the help
The code is as follows
abstract class Mammal {
    String name;
    Mammal(String n)
        name = n;
    void sleep()
        System.out.println( name + "! is asleep! zzzzzzz!");
    abstract void talk();
class Man extends Mammal {
    Man(String n)
        super(n);
    void talk()
        System.out.println("H1 My Name is "+name+" How do you do?");
class Dog extends Mammal {
    Dog(String n)
        super(n);
    void talk()
        System.out.println("Wrf!Wrf!");
public class Main {
    public static void main(String[] args) {
       Dog d1 = new Dog("Dots");
       Man m1 = new Man("Joe");
       Dog d2 = new Dog("Dollar");
       Man m2 = new Man("Mike");
       // ideally i would like to push this into collection of objects
}

Answer 1

standman wrote:
thank you
i tried this. If it is wrong please let me know. If all you need is a List, it may work fine. I didn't try it. Some suggestions:
Declare 'al' as a List:
List al = new ArrayList();Then if you decide you need a LinkedList or other List, you only have to change the right side construction.
Try to use generics (as YoungWinston suggested).
Use an Iterator or an "enhanced 'for' loop" for the iteration, instead of constantly checking "size" and using "get(i)". Since you have a short random-access list (ArrayList), your loop may work okay. But, if you had a long non-random-access list (such as LinkedList), an Iterator or "enhanced 'for' loop" (which uses an Iterator behind-the-scenes) would work faster.
If you do need thread-safety, there are other considerations, too.