1. CSC115 Introduction to Computer Programming Zhen Jiang Dept. of Computer Science West Chester University West Chester, PA 19383 zjiang@wcupa.edu

2. Table of Contents Structure Selection (Decision) Loop Array and Function

3. Price is right. Sample execution (click on this link to try)this link Selection (Decision)

4. Condition Yes Action 1Action 2 No Action 3

5. Boolean Expression Yes Action 1 If controlled Action 2 else controlled No Action 3 11/21/20155

6. If block if condition then action 1 (statements 1) else action 2 (statements 2) end if action 3 (statement 3)

7. Legal age to have driver’s license

9. Condition Simple condition Format Number value relational operators =, <>,, = String value relational operators =, <> Complex condition And, or, not Truth table, table 4, p121

10. Relational operators have lower precedence than math operators. 5 * 7 >= 3 + 5 * (7 - 1)‏ 5 * 7 >= 3 + 5 * 6 35 >= 3 + 30 35 >= 33 true Relational operators cannot be chained (unlike math operators) 2 <= x <= 10 error! 11/21/201510

11. Identify two exclusive options Implement each handling in different action parts Identify the situation (values) for option selection Make a condition so that all the situation value for option part 1 will lead to this condition true. Verify all the situation value for option part 2 will lead to this condition false, otherwise, revise the above condition! Development Process

13. Multiple selection Nested if block Example: letter grade

14. Comments: Nested if block for multiple section problem If then case 1 Else if then case 2 else … end if End if

15. If block, extension without else if condition then action 1 (statements 1) end if action 3 (statement 3)

16. Dim x as integer, y as integer x = text1.text y=0 if x > 3 then y =1 if x >10 then y = 2 else y = 3 End if Listbox1.Items.Add( y ) Try 2 Dim x as integer, y as integer x = text1.text y=0 if x > 3 then y =1 if x > 10 then y = 2 End if else y = 3 End if Listbox1.Items.Add( y )

17. Dim x as integer, y as integer x = text1.text y=0 if x > 3 then y =1 if x >10 then y = 2 else y = 3 End if Listbox1.Items.Add( y ) Dim x as integer, y as integer x = text1.text y=0 if x > 3 then y =1 if x > 10 then y = 2 End if else y = 3 End if Listbox1.Items.Add( y )

18. Select block Select case A constant A variable An expression Is To range Else And and or

19. Loop Do while Loop do while condition statements loop statements2

20. Yes statements1Action 2 No Action 3 condition

21. Yes Statements1 No Statements2 condition

22. Other loops

23. Clock

24. Function and procedure

25. Array