Statements That Repeat
For...Next Loop Structure
For counter = start To end Step increment statements Next counter Where Counter is tested to see if less than end. If so, repeat loop again. If not, go to statement after Next.
Do While...Loop Structure
Do While condition statements Loop Where The condition is tested, and if true the loop is repeated. When the condition is false, the loop statements are skipped the statement after Loop is executed.
Do Until...Loop Structure
Do Until condition statements Loop Where The condition is tested, and if false the loop is repeated. When the condition is true, the loop statements are skipped the statement after Loop is executed.
Do Until...Loop Structure
‘Calculate the factorial of a number given by user Dim Factorial As Double Dim I As Integer User gives number I = 1 Factorial = 1 Do While I <= Val (txtAnswer.text) Factorial = Factorial + 1 I = I + 1 Loop
Loops with the Marching Band Project
Hands-On Exercise 3 (P.134-145)
– – – – – – – – – – – Create the Marching Band Project Add Command Buttons and a Timer Add Controls to Display the Band Add Banner Comments Add Code for Buttons and the Form Add Code to Add Animation Run, Save, Test and Debug Your Project Create a Copy of the Project Change Animation Code Update, Run, Save, Test and Debug Exit Visual Basic
Summary ...
• • • • • • Fundamental programming demonstrated Variables vs. Constants Data types Local vs Global variables Functions and Procedures Control structures: sequence, selection and repetition
Summary
Statements
– Dim, Static, Const – Public, Private – Sub, Function – Do...Loop, Do While...Loop, Do Until...Loop – For Each...Next, For...Next – If...Then...Else – Select Case
Practice with Visual Basic
1. Learning to Subtract Game (P.148) 2. Wind Chill in Celsius (P.148) 3. Heat Index (P.148) 4. Rock, Paper, Scissors Game(P.150)
Case Studies
• • • • Calculate a Formula Weather Calculations More Fun and Games More Web Resources for Visual Basic
End of Lecture