Name
Do...Loop Statement
Syntax
Do [{While | Until}condition
] [statements
] [Exit Do] [statements
] Loop
or:
Do [statements
] [Exit Do] [statements
] Loop [{While | Until}condition
]
-
condition
(optional; Boolean expression) An expression that evaluates to
True
orFalse
-
statements
(optional) Program statements that are repeatedly executed while, or until,
condition
isTrue
Description
Repeatedly executes a block of code while or until a condition
becomes True
Rules at a Glance
On its own,
Do...Loop
infinitely executes the code that is contained within its boundaries. You therefore need to specify within the code under what conditions the loop is to stop repeating. In addition, if the loop executes more than once, the variable controlling loop execution must be modified inside of the loop. For example:Do intCtr = intCtr + 1 ' Modify loop control variable MsgBox("Iteration " & intCtr & " of the Do loop...") ' Compare to upper limit If intCtr = 10 Then Exit Sub Loop
Failure to do this results in the creation of an endless loop.
Adding the
Until
keyword afterDo
instructs your program toDo
somethingUntil
the condition isTrue
. Its syntax is:Do Until
condition
'code to execute LoopIf
condition
isTrue
before your code gets to theDo
statement, the code within theDo...Loop
is ignored.Adding the
While
keyword afterDo
repeats the code while a particular condition isTrue
. When the condition becomesFalse
, the loop is automatically exited. The syntax of theDo
While
statement is:Do While
condition ...
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