CS201 Final Exam Topics

The CS201 final exam is open book and open notes. You can use a computer to access notes or look at programs you (or I) may have written, but you are not allowed to compile programs or search for answers on the Internet. You have two hours and 45 minutes. The emphasis is on material covered since the midterm exam, but you will still need to know the basics from the prior material. The topics that will be covered are listed below, with a major emphasis on arrays, classes, inheritance/polymorphism, exceptions, file I/O, methods, and recursion.

Methods and Classes

• How to define a method
• Parameter passing
  • Pass by value for primitive data types -- contents of original variable in the caller unchanged
  • Pass by reference for objects -- contents of an object variable in the caller may be changed
• Concept of a class object and creating instances of the object
  • Class instance/member variables
  • Class methods
    • Creating a constructor
    • When a constructor is invoked
  • Public vs. Private  (vs. Protected)
    • Writing methods to access instance variables
    • Concept of encapsulation or information hiding
• Static
  • What happens when applied to methods, instance variables
• Scoping Rules
  • Be prepared to trace through a program with different parameter calls, scoping, and display the output!
• Method overloading (methods with the same name but different input parameters)

Arrays

• How to define a 1 to N dimensional array of some data type
• Accessing, initializing arrays
• Limitations on arrays
  • What if we use = on arrays?
  • What if we use == on arrays?
  • What if we exceed bounds of array?
  • Can we make an array bigger?
• Array as an object
  • How to pass an array to a function, pass by reference behavior
  • Array length

ArrayList and Generics

• Not on the final but you are welcome to use one in an answer if you wish

Pointers / Reference Variables

• What is stored in a reference variable when we create an object via "new" (i.e. address of object)
  • What happens when we assign a reference variable to another one

Inheritance

• Using "extends" to create a derived class from a base class, or "implements" to create a class derived from an interface
• What happens in derived class with base class variables, methods (public or private or protected)
• Using "super"
• Method overriding
  • Which method gets invoked when multiple names exist in the hierarchy
  • Difference from method overloading
• What we inherit from class Object
  • equals, toString
• Multiple types for multi-level inheritance
  • Assigning types going "up" is no problem
  • Must typecast if assigning "down"
  • Dynamic binding - Java invokes the method based on the type of the object when it is created using "new" not the current reference regardless of type
  • Concept of interfaces

Exceptions

• What an exception is
• try, catch
• Exception object, using different exception classes (IOException, NumberFormatException, etc.)

File I/O

• Be able to read data (strings, ints, doubles, etc.) from a text file
• Be able to write data to a text file

Recursion

• Write a short recursive program
• Idea of a base case / termination condition, recursive call