Why do we use virtual and override?

Question

Why do we use override and virtual if it gives the same effect when we dont use override and virtual?

example 1:

class BaseClass
{
    public virtual         


        

Answer 1

Best example I can think of where this is useful is when you create your own object(class) and you have to add a list of that object to a combobox.

When you add your object to the combobox you want to be able to control what text is displayed for each item. Object.toString is a virtual method. http://msdn.microsoft.com/en-us/library/system.object.tostring.aspx and because of this you can override that method and set .toString to display the correct information about your object by overriding it.

public MyClass()
{
     private int ID;
     public override string ToString()
     {
         return "My Item:" + ID;
     }
}