The For Loop
The For...Next
statement provides a
method for repeatedly
looping through a block of code (that is,
one or more lines of code). This loop is naturally referred to as a
For
loop. The basic syntax is:
For counter = start To end ' block of code goes here . . . Next counter
The first time that the block of code is executed, the variable
counter
(called the loop variable for the
For
loop) is given the value
start
. Each subsequent time that the block
of code is executed, the loop variable counter
is
incremented by 1. When counter
exceeds the value
end
, the block of code is no longer executed.
Thus, the code block is executed a total of end
-
start
+
1
times, each time with a different value of
counter
.
Note that we can omit the word counter
in
the last line of a For
loop (replacing
Next
counter
with just
Next
). This may cause the For
loop to execute a bit more quickly, but it also detracts a bit from
readability.
To illustrate, the following code prints the names of the fields in the Objects table:
Sub PrintFields() Dim i As Integer Dim rs As Recordset Set rs = CurrentDb.OpenRecordset("Objects") For i = 0 To rs.Fields.Count - 1 Debug.Print rs.Fields(i).Name Next rs.Close End Sub
Note that the limits of the For
statement are
to rs.Fields.Count
-
1
because the fields are indexed starting at
(rather than 1). We will discuss this issue in more detail when we
talk about DAO programming.
For
loops are often used to initialize an array.
For instance, the code:
For i = 0 To 10 iArray(i) ...
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