Csharp/C Sharp/Language Basics/If

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);
          }
       }
    }
 }

Demonstrate a block of code

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Demonstrate a block of code. 
 
using System; 
 
public class BlockDemo { 
  public static void Main() { 
    int i, j, d; 
 
    i = 5; 
    j = 10; 
 
    // the target of this if is a block 
    if(i != 0) { 
      Console.WriteLine("i does not equal zero"); 
      d = j / i; 
      Console.WriteLine("j / i is " + d); 
    } 
  } 
}

Demonstrate the if

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Demonstrate the if.  
 
using System; 
 
public class IfDemo {  
  public static void Main() {  
    int a, b, c;  
  
    a = 2;  
    b = 3;  
  
    if(a < b) Console.WriteLine("a is less than b"); 
 
    // this won"t display anything  
    if(a == b) Console.WriteLine("you won"t see this");  
 
    Console.WriteLine(); 
 
    c = a - b; // c contains -1 
 
    Console.WriteLine("c contains -1"); 
    if(c >= 0) Console.WriteLine("c is non-negative"); 
    if(c < 0) Console.WriteLine("c is negative"); 
 
    Console.WriteLine(); 
 
    c = b - a; // c now contains 1 
    Console.WriteLine("c contains 1"); 
    if(c >= 0) Console.WriteLine("c is non-negative"); 
    if(c < 0) Console.WriteLine("c is negative"); 
 
  }  
}

Determine if a value is positive, negative, or zero

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Determine if a value is positive, negative, or zero. 
using System; 
 
public class PosNegZero {  
  public static void Main() { 
    int i; 
 
    for(i=-5; i <= 5; i++) { 
 
      Console.Write("Testing " + i + ": "); 
 
      if(i < 0) Console.WriteLine("negative"); 
      else if(i == 0) Console.WriteLine("no sign"); 
        else Console.WriteLine("positive"); 
    } 
 
  } 
}

Determine if a value is positive or negative

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Determine if a value is positive or negative. 
using System; 
 
public class PosNeg {  
  public static void Main() { 
    int i; 
 
    for(i=-5; i <= 5; i++) { 
      Console.Write("Testing " + i + ": "); 
 
      if(i < 0) Console.WriteLine("negative"); 
      else Console.WriteLine("positive"); 
    } 
 
  } 
}

If Branching

/*
Learning C# 
by Jesse Liberty
Publisher: O"Reilly 
ISBN: 0596003765
*/
 using System;
 namespace Branching
 {
    public class TestBranching
    {
       static void Main()
       {
             int valueOne = 10;
             int valueTwo = 20;
             int valueThree = 30;
             Console.WriteLine("Testing valueOne against valueTwo...");
             if ( valueOne > valueTwo )
             {
                 Console.WriteLine(
                 "ValueOne: {0} larger than ValueTwo: {1}",
                 valueOne, valueTwo);
             }
             Console.WriteLine("Testing valueThree against valueTwo...");
             if ( valueThree > valueTwo )
             {
                 Console.WriteLine(
                     "ValueThree: {0} larger than ValueTwo: {1}",
                     valueThree, valueTwo);
             }   // end if
       }         // end Main
    }            // end class
 }               // end namespace

If Else

/*
Learning C# 
by Jesse Liberty
Publisher: O"Reilly 
ISBN: 0596003765
*/
 using System;
 namespace Branching
 {
     public class TestIfElse
     {
         static void Main()
         {
             int valueOne = 10;
             int valueTwo = 20;
             Console.WriteLine("Testing valueOne against valueTwo...");
             if ( valueOne > valueTwo )
             {
                 Console.WriteLine(
                     "ValueOne: {0} larger than ValueTwo: {1}",
                     valueOne, valueTwo);
             }       // end if
             else
             {
                 Console.WriteLine(
                     "Nope, ValueOne: {0} is NOT larger than ValueTwo: {1}",
                     valueOne, valueTwo);
             }       // end else
         }           // end Main
     }               // end class
 }                   // end namespace

If else for int

/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 */
using System;
namespace Client.Chapter_4___Program_Control
{
  public class ifelse
  {
    static void Main(string[] args)
    {
      int a = 5, b = 5, c = 10;
      if (a == b)
        Console.WriteLine(a);
      if ((a > c) || (a == b))
        Console.WriteLine(b);
      if ((a >= c) && (b <= c))
        Console.WriteLine(c);
    }
  }
}

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!");
      }
    }
  }
}

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);
    }
  }
}

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);
  }
}

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!");
    }
  }
}