Computer Programming Concepts and Visual Basic David I. Schneider

Private Sub cmdDisplay_Click()
Dim pop As Single, yr As Integer
‘Display population from 1998 to 2002
picTable.Cls
pop = 300000
For yr = 1998 To 2002
picTable.Print yr, FormatNumber(pop, 0)
pop = pop + .03 * pop
Next yr
End Sub
[Run, and click the command button.]
The initial and terminating values can be constants, variables, or expressions. For
instance, the For statement in the preceding program can be replaced by
firstYr = 1998
lastYr = 2002
For yr = firstYr To lastYr
In Example 1, the control variable was increased by 1 after each pass through the loop.
A variation of the For statement allows any number to be used as the increment. The statement
For i= m To n Step s
instructs the Next statement to add s to the control variable instead of 1. The numbers m, n,
and s do not have to be whole numbers. The number s is called the step value of the loop.
EXAMPLE 2
The following program displays the values of the index of a For...Next loop for terminating and step values
input by the user.
Object Property Setting
frm6_3_2 Caption For index = 0 To n Step s
lblN Caption n:
txtEnd Text (blank)
lblS Caption s:
txtStep Text (blank)
cmdDisplay Caption Display Values of index
picValues
Private Sub cmdDisplay_Click()
Dim n As Single, s As Single, index As Single
‘Display values of index ranging from 0 to n Step s
picValues.Cls
n = Val(txtEnd.Text)
s = Val(txtStep.Text)
For index = 0 To n Step s
For...Next Loops 143