Do...Loop Statement

Description

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 equally valid syntax:

Do
[statements]
[Exit Do]
[statements]
Loop [{While | Until} condition]

The Do...Loop statement syntax has these parts:

Part Description
condition Numeric 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

The Exit Do can only be used within a Do...Loop control structure to provide an alternate way to exit a Do...Loop. Any number of Exit Do statements may be placed anywhere in the Do...Loop. Often used with the evaluation of some condition (for example, If...Then), Exit Do 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 it occurs.

See Also

Exit Statement, For...Next Statement, While...Wend Statement.

Example

This example shows how Do...Loop statements can be used. The inner Do...Loop statement loops 10 times, sets the value of the flag to False, and exits prematurely using the Exit Do statement. The outer loop exits immediately upon checking the value of the flag.


Check = True: Counter = 0    ' Initialize variables.                ' Outer loop.
    Do While Counter < 20    ' Inner loop.
        Counter = Counter + 1    ' Increment Counter.
        If Counter = 10 Then    ' If condition is True.
            Check = False    ' Set value of flag to False.
            Exit Do    ' Exit inner loop.
        End If
    LoopUntil Check = False    ' Exit outer loop immediately.