1
CS 112 Introduction to
Programming
Lecture #23:
Characters;
More on Classes and Objects
http://flint.cs.yale.edu/cs112/
2
Recap: Two Types of Double-Subscripted Arrays
rRectangular arrays
int[,] array1 = new int[,] { { 1, 2, 3 }, { 4, 5, 6 } };
int[,] array11 = new int[3,4];
array1[0,2] = 10;
rJagged arrays
int[][] array2 = new int[ 3][];
array2[ 0 ] = new int[] { 1, 2 };
array2[ 1 ] = new int[] { 3 };
array2[ 2 ] = new int[] { 4, 5, 6 };
array2[2][1] = 3;
3
Recap: Class String
rA string is essentially an encapsulation of an array of
characters
rSince we use string so often, C# defines the string
class and provides many methods (see link on the
schedule page), e.g.,
mConstructors, CopyTo, Format, Substring, Concat
mCompareTo, Equals, ==, !=, StartsWith,
EndsWith, IndexOf, IndexOfAny, LastIndexOf,
LastIndexOfAny
mToUpper, ToLower, Trim, Replace, Insert,
Split
rA related class: StringBuilder (linked on the
lecture-notes page)
4
Outline
rAdmin.
ØCharacters
qAn introduction to inheritance
5
Char Methods
rFor the char value type, there is a Char class
rMost methods are static
mIsLetter
mIsDigit
mIsLetterOrDigit
mIsLower
mIsUpper
mToUpper
mToLower
mIsPunctuation
mIsSymbol
mIsWhiteSpace
Outline
CharMethods.cs
1 // StaticCharMethods.cs
2 // Demonstrates static character testing methods
3 // from Char structure
4
5 using System;
6 using System.Drawing;
7 using System.Collections;
8 using System.ComponentModel;
9 using System.Windows.Forms;
10 using System.Data;
11
12 // Form displays information about specific characters.
13 public class StaticCharMethods : System.Windows.Forms.Form
14 {
15 private System.Windows.Forms.Label enterLabel;
16 private System.Windows.Forms.TextBox inputTextBox;
17 private System.Windows.Forms.Button analyzeButton;
18 private System.Windows.Forms.TextBox outputTextBox;
19
20 private System.ComponentModel.Container components = null;
21
22 // The main entry point for the application.
23 [STAThread]
24 static void Main()
25 {
26 Application.Run( new StaticCharMethods() );
27 }
28
29 // Visual Studio .NET generated code
30
