Repeats a block of statements while a condition is True or until a condition becomes True.
Syntax
Do [{ While | Until } condition ] [ statements ] [ Exit Do ] [ statements ] Loop
Or, you can use this syntax:
Do [ statements ] [ Exit Do ] [ statements ] Loop [{ While | Until } condition ]
The Do Loop statement syntax has these parts:
Part | Description |
---|---|
condition | Optional. Numeric expression or string expression that is True or False. If condition is Null, condition is treated as False. |
statements | One or more statements that are repeated while, or until, condition is True. |
Remarks
Any number of Exit Do statements may be placed anywhere in the Do…Loop as an alternate way to exit a Do…Loop. Exit Do is often used after evaluating some condition, for example, If…Then, in which case the Exit Do statement transfers control to the statement immediately following the Loop.
When used within nested Do…Loop statements, Exit Do transfers control to the loop that is one nested level above the loop where Exit Do occurs.
Examples
This example shows how Do...Loop statements can be used. The inner Do...Loop statement loops 10 times, asks the user if it should keep going, sets the value of the flag to False when they select No, and exits prematurely by using the Exit Do statement. The outer loop exits immediately upon checking the value of the flag.
Public Sub LoopExample()
Dim Check As Boolean, Counter As Long, Total As Long
Check = True: Counter = 0: Total = 0 ' Initialize variables.
Do ' Outer loop.
Do While Counter < 20 ' Inner Loop
Counter = Counter + 1 ' Increment Counter.
If Counter Mod 10 = 0 Then ' Check in with the user on every multiple of 10.
Check = (MsgBox("Keep going?", vbYesNo) = vbYes) ' Stop when user click's on No
If Not Check Then Exit Do ' Exit inner loop.
End If
Loop
Total = Total + Counter ' Exit Do Lands here.
Counter = 0
Loop Until Check = False ' Exit outer loop immediately.
MsgBox "Counted to: " & Total
End Sub