CS 112 Introduction to Programming

1
CS 112 Introduction to Programming

• Lecture 37
• Review
• Http//zoo.cs.yale.edu/classes/cs112/

2
Admin.

• Exam 2 Thursday (tomorrow) evening
• location DL 220
• time 7-9 PM
• office hours
• Wednesday (today)
• 2-3 PM (AKW 202)
• 8-1030 PM (DL 120)
• Thursday
• 3-430 PM (DL 120)

3
Basic Topics Covered

• Arrays (4)
• strings
• Object-oriented programming (4)
• GUI/event driven programming/graphics (4)
• Recursion
• recursive methods (4)
• recursive data structures (1)
• Exception handling (1)

4
Arrays Declaration, Initialization, and Access

• 1D array
• int array1 new int 1, 2, 3
• int array2 new int3
• array12 10
• Multi-dimensional array
• rectangular arrays
• int, array3 new int, 1, 2, 3 , 4, 5,
  6
• int, array4 new int3,4
• jagged arrays
• arrays of arrays
• arrays that compose jagged arrays can be of
  different lengths, e.g.,
• int array5 new int 3 array5 0
  new int 1, 2 array5 1 new int 3
  array5 2 new int 4, 5, 6
  array521 3

5
Array A String As Character Array

• A string is essentially an encapsulation of an
  array of characters
• string str abc
• Console.WriteLine( str0 )
• static void Main( string args )
• Console.WriteLine( args01 )
• Some commonly used functions of the String class
• method ToUpper
• method ToLower
• method Format

6
Array Some Usage

• Store multiple data items
• Same type
• Related with polymorphism
• Array elements as counters

7
Object-Oriented Design Inheritance

• Why inheritance
• code reuse
• polymorphism (extensible and elegant design)
• Controlling inheritance
• private, protected, public
• override, virtual
• Class hierarchy the object class ToString()
• Extending the basic idea of inheritance
• Abstract class
• Interface

8
GUI

• Example components/controls
• Label
• TextBox
• Button
• PictureBox
• Timer
• Media Player MS Agent
• Controlling layout of a Windows application
• GroupBox and Panel
• Anchor and Dock
• Events and event handler
• Buttons, e.g., Click event
• Mouse, e.g., MouseDown, MouseUp, MouseMove
• Keyboard, e.g., KeyPress
• Timer

9
Graphics

• Graphics
• Graphics context coordinate system some
  graphics methods, e.g., DrawLine Pen
• When to draw OnPaint, Paint event handler, and
  Invalidate method call extract graphics context
  from argument, i.e., e.Graphics

10
Recursion

• Recursive methods
• define method structure
• define recursive case
• define base case
• recursive search
• keep state, e.g., Maze
• backtrack, e.g., Knights tour
• Recursive data structures
• linked list
• definition
• implementation of enumeration, insertions and
  deletions for linked lists
• other potential recursive data structures
• choose the right data structure array or linked
  list

11
Exceptions

• Why exception?
• Some common exceptions
• System.Exception
• System.SystemException
• System.FormatException
  System.ArithmeticException
• System.DivideByZeroException
• System.OverflowException
  System.IndexOutOfRangeException
• Properties Message, StatckTrace
• How to handle exceptions catch, try, and finally

12
Summary

• storing data
• primitive data types
• classes (inheritance access control)
• arrays
• recursive data structure
• processing data
• expressions
• flow of control (e.g., while, for, do/while)
• methods (overload virtual/override
  decomposition)
• recursive methods
• exceptions
• links between storage and processing
• classes (encapsulation)
• data structures (pick efficient storage for
  required processing)