Subclass

gistfile1.java

// SubClass with Method Override 

public virtual class myParentClass {

public virtual void dosomething()
{
 System.Debug('Something');

}

public class myclass extends myParentClass
{
 public override void dosomething()
{
 super.dosomething();
 System.Debug('something else');
}

new myclass().dosomething();

}


//Abstract Method and Override

public abstract class myBaseClass{
public abstract void dosomething ();
}

public class MyClass extends myBaseClass{

public override void dosomething()
{
System.Debug('something');
}
}
 new MyClass.dosomething();


// Using instanceof Keyword

List <ClassA> newList  = new List<ClasA>();
newList.add(new ClassA());
newList.add(new ClassB());
System.Debug(newList.get(2) instancof ClassB);