VB.Net Tutorial/Statements/If

ElseIf

public class Test
   public Shared Sub Main
        Dim intScore As Integer
        Dim strResult As String
        intScore = 78
        If intScore < 50 Then
            strResult = "Failed."
        ElseIf intScore < 75 Then
            strResult = "Pass."
        ElseIf intScore < 90 Then
            strResult = "Very Good."
        Else
            strResult = "Excellent."
        End If
        Console.WriteLine(strResult)

   End Sub

End class

Very Good.

Else If (Not ELSEIF)

Imports System
Public Class Test
     Shared Sub Main()
        Dim dtCurrent As System.DateTime
        Dim iHour As Integer
        dtCurrent = dtCurrent.Now()
        iHour = dtCurrent.Hour
        If (iHour < 12) Then
            Console.Writeline("Good Morning!")
        Else If (iHour >= 12) And (iHour < 18) Then
               Console.WriteLine("Good Afternoon!")
        Else
            Console.WriteLine("Good Evening!")
        End If
    End Sub
End Class

Very Good.

If Short Circuiting with ANDALSO

Public Class ShortCircuiting
     Shared Sub Main()
         If Test("Left") ANDALSO Test("Right") Then
             "do something
         End If
     End Sub
 
     Shared Function Test(sInput As String) As Boolean
         System.Console.WriteLine(sInput)
         Test = FALSE
     End Function
End Class

Left

If statement Short Circuiting

Public Class ShortCircuiting
     Shared Sub Main()
         If Test("Left") AND Test("Right") Then
             "do something
         End If
     End Sub
 
     Shared Function Test(sInput As String) As Boolean
         System.Console.WriteLine(sInput)
         Test = FALSE
     End Function
End Class

Left
Right

If with And

Imports System
Public Class Test
     Shared Sub Main()
        Dim dtCurrent As System.DateTime
        Dim iHour As Integer
        dtCurrent = dtCurrent.Now()
        iHour = dtCurrent.Hour
        If (iHour < 12) Then
            Console.Writeline("Good Morning!")
        ElseIf (iHour >= 12) And (iHour < 18) Then
            Console.WriteLine("Good Afternoon!")
        Else
            Console.WriteLine("Good Evening!")
        End If
    End Sub
End Class

Good Afternoon!

Nested if statement

Option Strict On
 Imports System
 Module Module1
    Sub Main( )
       Dim temp As Integer = 32
       If temp <= 32 Then
          If temp = 32 Then
             Console.WriteLine("temp = 32")
          Else
             Console.WriteLine("Temp: {0}", temp)
          End If
       End If 
    End Sub 
 End Module

temp = 32

Single line vs Multi-line If statement

public class Test
   public Shared Sub Main
        Dim intScore As Integer
        intScore = 23
        "Single line If statement.
        If intScore < 50 Then Console.WriteLine("Failed.") : Console.WriteLine("Please try again.")

        "Multi-line If statement.
        If intScore < 50 Then
            Console.WriteLine("Failed.")
            Console.WriteLine("Please try again.")
        End If
   End Sub

End class

Failed.
Please try again.
Failed.
Please try again.

Use ElseIf

Option Strict On
 Imports System
 Module Module1
    Sub Main( )
       Dim temp As Integer = -32
       If temp > 32 Then
       ElseIf temp = 32 Then
          Console.WriteLine("= 32")
       ElseIf temp > 0 Then
       ElseIf temp = 0 Then
          Console.WriteLine(" = 0")
       Else
          Console.WriteLine("Else")
       End If
    End Sub "Main
 End Module

Else

Use If statement in a For statement

public class Test
   public Shared Sub Main
        Dim intCounter As Integer
        Dim strString As String = "some silly string"
        For intCounter = 0 To strString.Length - 1
            If strString(intCounter) = "s" Then
                strString = strString.Remove(intCounter, 1)
                strString = strString.Insert(intCounter, "S")
            End If
        Next intCounter
        Console.WriteLine(strString)
   End Sub

End class

Some Silly String

Use if statement to compare Integer

Option Strict On
 Imports System
 Module Module1
    Sub Main( )
       Dim valueOne As Integer = 10
       Dim valueTwo As Integer = 20
       Dim valueThree As Integer = 30
       If valueOne > valueTwo Then
          Console.WriteLine("ValueOne: {0} larger than ValueTwo: {1}", valueOne, valueTwo)
       End If
       If valueThree > valueTwo Then
          Console.WriteLine("ValueThree: {0} larger than ValueTwo: {1}",valueThree, valueTwo)
       End If
       If valueTwo > 15 Then 
            Console.WriteLine("Yes it is")
       End If
    End Sub "Main
 End Module

ValueThree: 30 larger than ValueTwo: 20
Yes it is