using System; public interface IPrintMessage { void Print(); }; class Class1 { public void Print() { Console.WriteLine("Hello from Class1!"); } } class Class2 : IPrintMessage { public void Print() { Console.WriteLine("Hello from Class2!"); } } class MainClass { public static void Main() { PrintClass PrintObject = new PrintClass(); PrintObject.PrintMessages(); } } class PrintClass { public void PrintMessages() { Class1 Object1 = new Class1(); Class2 Object2 = new Class2(); PrintMessageFromObject(Object1); PrintMessageFromObject(Object2); } private void PrintMessageFromObject(object obj) { if(obj is IPrintMessage) { IPrintMessage PrintMessage; PrintMessage = (IPrintMessage)obj; PrintMessage.Print(); } } }
Use internal
/* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852 */ // Use internal. using System; class InternalTest { internal int x; } public class InternalDemo { public static void Main() { InternalTest ob = new InternalTest(); ob.x = 10; // can access -- in same file Console.WriteLine("Here is ob.x: " + ob.x); } }
Logical operators with an if statement
/* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110 */ /* Example4_4.cs illustrates the use of logical operators with an if statement */ public class Example4_4 { public static void Main() { int reactorTemp = 1500; string emergencyValve = "closed"; if ((reactorTemp > 1000) && (emergencyValve == "closed")) { System.Console.WriteLine("Reactor meltdown in progress!"); } } }
illustrates the use of a nested if statement
/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
Example4_3.cs illustrates the use of
a nested if statement
*/
public class Example4_3
{
public static void Main()
{
int reactorTemp = 1500;
string emergencyValve = ” “;
if (reactorTemp < 1000) { System.Console.WriteLine("Reactor temperature normal"); } else { System.Console.WriteLine("Reactor temperature too high!"); if (emergencyValve == "closed") { System.Console.WriteLine("Reactor meltdown in progress!"); } } } } [/csharp]
Illustrates the use of an if statement that executes a block
/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
Example4_2.cs illustrates the use of an if statement
that executes a block
*/
public class Example4_2
{
public static void Main()
{
int smallNumber = 5;
int bigNumber = 100;
if (bigNumber < smallNumber) { System.Console.Write(bigNumber); System.Console.Write(" is less than "); System.Console.Write(smallNumber); } else { System.Console.Write(smallNumber); System.Console.Write(" is less than "); System.Console.Write(bigNumber); } } } [/csharp]
Illustrates the use of the if statement
/* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110 */ /* Example4_1.cs illustrates the use of the if statement */ public class Example4_1 { public static void Main() { int smallNumber = 5; int bigNumber = 100; if (bigNumber > smallNumber) System.Console.WriteLine(bigNumber + " is greater than " + smallNumber); else System.Console.WriteLine(bigNumber + " is less than " + smallNumber); } }
Another if else
/*
Learning C#
by Jesse Liberty
Publisher: O'Reilly
ISBN: 0596003765
*/
using System;
public class NestIfValues
{
static void Main()
{
int temp = 32;
if (temp <= 32) { Console.WriteLine("Warning! Ice on road!"); if (temp == 32) { Console.WriteLine( "Temp exactly freezing, beware of water."); } else { Console.WriteLine("Watch for black ice! Temp: {0}", temp); } } } } [/csharp]