Abstract Class question

[maa11235]

If it is true that one can not instantiate an object from an abstract class, why is it that classes like AbstractCollection have a constructor?

maa11235

[tim]

Hello maa11235

It is true that abstract classes cannot be instanced. They are used as a structure to extend from. Abstract classes can contain variables and non-abstract methods. The constructor is used to call the required methods, whether they are abstract or not, and initialize any variables. The reason that an abstract class can have a constructor is so that it's subclass can call that constructor by using the super(<arguments here>) constructor. This style of programming can significantly shorten your code.

Hope that helped.