If condition Then code to execute if true ElseIf condition Then code Else code to execute if conditions are both false End If
For I as Integer = 1 To 10 Step 1 code to execute Next
Step is optional and Step 1 is the default. Step tells it how to count, so -1 would have it subtract 1 each time and Step 5 would have it add 5 each time thru the loop.
In case the loop need to be stopped, then the
Exit For statement can be used, as in the below example;
Dim iIndex as integer For I as Integer = 1 To 10 Step 1 Debug.Print I iIndex = I * 10 If iIndex > 90 Then Exit For End If Loop
Here, instead of printing 1 to 10, it will stop at 9, since the condition told the process to stop when iIndex reaches 90.
Another common type of loop in Visual Basic is the
DO loop, which would run a piece of code continuously until it is told to stop. On the contrary of some other loops whereby indexes are used to stop the process, in this particular loop, it should be told to stop.
A simple example illustrating the loop is as follows
Dim iIndex1 As Integer iIndex1 = 1 Do Debug.Print iIndex1 iIndex1 = iIndex1 + 1 If iIndex1 = 10 Then Exit Do End If Loop
The above piece of code will take an Index, initialized to 1, and increment it. A
Debug.Print will help print the index to rack the loop. On each loop, the code will verify if the index has reached 10 and if and only if the condition is true, the
Exit Do will be executed, which will stop the loop.
Dim number As Integer = 8 Select Case number Case 1 To 5 Debug.WriteLine("Between 1 and 5, inclusive") ' The following is the only Case clause that evaluates to True. Case 6, 7, 8 Debug.WriteLine("Between 6 and 8, inclusive") Case 9 To 10 Debug.WriteLine("Equal to 9 or 10") Case Else Debug.WriteLine("Not between 1 and 10, inclusive") End Select