2. Looping Structures Do Loops, For Next

3. Do...Loop While structures check the condition after executing the code and repeat a code block until the test expression evaluates as false. Do strPassword = InputBox("Enter your password") Loop While strPassword <> "Lefty" The example code will loop until the correct password is entered

4. Do...Loop Until structures check the condition after executing the code and repeat a code block until the test expression evaluates as true. Dim intLoopCount As Integer Do intLoopCount = intLoopCount + 1 Loop Until MsgBox("Loop?", vbYesNo) = vbNo The example code will loop until the No button is clicked in a message box.

5. Do While...Loop structures check the condition before executing the code. The code in the loop is executed only if the condition evaluates as true, and repeats until the test expression evaluates as false. Dim strPasswordTry As String Const PASSWORD As String = "password" Do While strPasswordTry <> PASSWORD strPasswordTry = InputBox("Enter password") Loop The example code will ask the user for a password until the correct password is typed into the input box

6. Do Until...Loop structures check the condition before executing the code. The code in the loop is executed only if the condition evaluates as false, and repeats until the test expression evaluates as true. Dim intValue As Integer Dim strInput As String Do Until intValue = 3 strInput = InputBox("Pick a number between 1 and 5") intValue = Val(strInput) Loop

7. CHALLENGE: Dim strMsg As String Dim strFilespec As String Dim strMatch As String strMsg = "Enter a file specification." 'Get file extension strFilespec = InputBox(strMsg) 'Find first match strMatch = Dir(strFilespec) Do Until Len(strMatch) = 0 'Display matching files MsgBox strMatch 'Find next match strMatch = Dir() Loop MsgBox "There are no more matching files."

8. When both the condition and the number of times a code block will execute is known, use a For loop. For counter = start To end [Step increment] [statements] Next [counter]

9. Dim intNumStudents As Integer Dim intCounter As Integer Dim sglScore As Single Dim sglTotalScore As Single Dim sglAverage As Single intNumStudents = InputBox(prompt:="How many students?") For intCounter = 1 To intNumStudents sglScore = CSng(Val(InputBox(prompt:="Enter score"))) sglTotalScore = sglTotalScore + sglScore Next intCounter sglAverage = sglTotalScore / intNumStudents The following example code displays an input box that prompts the user to enter a number. It then executes the code in the For...Next loop the specified number of times, calculating and displaying a result.

10. Dim intOuter As Integer, intInner As Integer Dim strOut As String ' Outer Loop For intOuter = 1 To 10 ' Inner Loop For intInner = 1 To 10 ' Concatenate Outer * Inner results to strOut strOut = strOut & " " & Format(intOuter * intInner, "@@@") Next intInner ' Add a carriage return and linefeed to end of line strOut = strOut & vbCrLf Next intOuter ' Monospaced font Me.Font = "Courier New" ' Display strOut on form Me.Print strOut The first For...Next loop generates each new line within the table. The second For...Next loop is nested within the first and generates each column within a row