VB.Net Tutorial/Statements/Select
Содержание
- 1 Select Case statement with Integer and exact value
- 2 Select Case statement with range Integer value
- 3 Select Case statement with String range value
- 4 Select Now.DayOfWeek
- 5 Specify several values in one Case statement
- 6 Use both range and fix value in Select statement
- 7 Using Select Case structure
Select Case statement with Integer and exact value
<source lang="vbnet">Option Strict On
Imports System Module Module1 Sub Main( ) Dim targetInteger As Integer = 15 Select Case targetInteger Case 5 Console.WriteLine("5") Case 10 Console.WriteLine("10") Case 15 Console.WriteLine("15!") Case Else Console.WriteLine("Value not found") End Select End Sub "Main End Module</source>
15!
Select Case statement with range Integer value
<source lang="vbnet">Option Strict On
Imports System Module Module1 Sub Main( ) Dim targetInteger As Integer = 7 Select Case targetInteger Case Is < 10 Console.WriteLine("Less than 10") Case 10 To 14 Console.WriteLine("10-14") Case 15 Console.WriteLine("15!") Case Else Console.WriteLine("Value not found") End Select End Sub "Main End Module</source>
Less than 10
Select Case statement with String range value
<source lang="vbnet">Option Strict On
Imports System Module Module1 Sub Main( ) Dim target As String = "M" Select Case target Case "A" To "L" Console.WriteLine("A To L executed") Case "L" To "Z" Console.WriteLine("L To Z executed") Case Else Console.WriteLine("Else executed") End Select End Sub "Main End Module</source>
L To Z executed
Select Now.DayOfWeek
<source lang="vbnet">public class Test
public Shared Sub Main
Dim strMessage As String Select Case Now.DayOfWeek Case DayOfWeek.Monday strMessage = "Have a nice week." Case DayOfWeek.Friday strMessage = "Have a nice weekend." Case Else strMessage = "Welcome back!" End Select Console.WriteLine(strMessage) End Sub
End class</source>
Have a nice weekend.
Specify several values in one Case statement
<source lang="vbnet">public class Test
public Shared Sub Main Select Case "Bird" Case "Bird" Console.WriteLine("This animal has 2 legs.") Case "Horse", "Dog", "Cat" Console.WriteLine("This animal has 4 legs.") Case "Snake" Console.WriteLine("This animal has no legs.") Case "Centipede" Console.WriteLine("This animal has 100 legs.") Case Else Console.WriteLine("You did not select from the list!") End Select End Sub
End Class</source>
This animal has 2 legs.
Use both range and fix value in Select statement
<source lang="vbnet">Module Module1
Sub Main() Dim intInput As Integer = 12 Select Case intInput Case 1 Console.WriteLine("Thank you for the 1.") Case 2 To 5 Console.WriteLine("Your value was 2, 3, 4, or 5") Case Is > 5 Console.WriteLine("That was greater than 5.") Case Else Console.WriteLine("Sorry, I can"t deal with that.") End Select End Sub
End Module</source>
That was greater than 5.
Using Select Case structure
<source lang="vbnet">Module Tester
Sub Main() Dim grade As Integer = 89 Dim aCount As Integer = 0 Dim bCount As Integer = 0 Dim cCount As Integer = 0 Dim dCount As Integer = 0 Dim fCount As Integer = 0 Select Case grade Case 100 Console.WriteLine("Perfect Score!" & vbCrLf & "Letter grade: A" & vbCrLf) aCount += 1 Case 90 To 99 Console.WriteLine("Letter Grade: A" & vbCrLf) aCount += 1 Case 80 To 89 Console.WriteLine("Letter Grade: B" & vbCrLf) bCount += 1 Case 70 To 79 Console.WriteLine("Letter Grade: C" & vbCrLf) cCount += 1 Case 60 To 69 Console.WriteLine("Letter Grade: D" & vbCrLf) dCount += 1 Case 0, 10 To 59 Console.WriteLine("Letter Grade: F" & vbCrLf) fCount += 1 Case Else Console.WriteLine("Invalid Input. " & _ "Please enter a valid grade." & vbCrLf) End Select End Sub
End Module</source>
Letter Grade: B