For ..... Next Repetition Statement:
To demonstrate the working of for .. next control statement, put a command button and a label control on the form. The Handle clicks the event for the command button. Now type the coding shown below as the event handler.
Private Sub Command1_Click()
Label1.Caption = "for loop illustration"
For i = 1 To 10
Form1.Print " the value of i is"; i
Next
End Sub
The Label control cannot be navigated. Whenever you press the tab key during the execution, the order in which the controls will be visited will be highlighted for every tab press. This is termed as the tab order. The Label control will not have a tab order. Primarily the Label control is used for displaying the heading. You set the caption property of the label control. During execution the caption will be exhibited on the form where the label control is placed. The common syntax of for loop is as shown below:
For index = initial value to end value (Step value)
One or more VB statements
Next
The for loop uses an index, namely "i", in this demonstration. The index is assigned the starting value, namely 1 as given. The keyword "To" tell the collection of values the index can take. The integer following "to" is the final value that is 10 in this illustration. Therefore, i, will start with 1 and raise by 1 till it reaches to 10. For each and every value of i, the statements between for and the next would be executed.
When the button is clicked "for loop illustration" will be displayed in the position where label control was placed. The following output would also be displayed on the screen as shown in figure.
the value of i is 1
the value of i is 2
the value of i is 3
....
the value of i is 10
Figure: Illustration of for next control statement
Specifying the Step Value:
For i = 10 To 1 Step -1
In the former for statement Step was not explicitly stated. Whenever it is not explicitly stated it is taken as 1 by default. In the above statement, the Step is specified as -1. Therefore the value will be decremented by 1 for each iteration. The index starts with 10 and is decremented by 1 for each iteration until it reaches to 1.