347: Highlights

• If no instances are to be created for a particular class, then you should tell Java that the class is an abstract class by instantiating the following pattern:

  public abstract class class name { 
   ... 
  } 
  

• If you want every subclass of an abstract class to define a particular method, then you should define an abstract method in the abstract class by instantiating the following pattern:

  public abstract return type method name  
   (parameter specifications) ; 
  

• You can use abstract class names as variable or parameter type declarations.