A. The description of the class and its purpose
B. A list of methods in its super class
C. A list of member variable
D. The class hierarchy

A. Declaration of primitive types such as boolean， byte and so on does not allocate memory space for the variable.
B. Declaration of primitive types such as boolean， byte and so on allocates memory space for the variable.
C. Declaration of nonprimitive types such as String， Vector and so on does not allocate memory space for the object.
D. Declaration of nonprimitive types such as String， Vector ans so on allocates memory space for the object.