2. Chapter Topics 11.1 Introduction to Menu-Driven Programs
11.2 Modularizing a Menu-Driven Program
11.3 Using a Loop to Repeat the Menu
11.4 Multiple-Level Menus

3. 11.1 Introduction to Menu-Driven Programs
A menu is a list of operations that are displayed by a program, in which a user can select which operations to perform
Figure A menu

4. 11.1 Introduction to Menu-Driven Programs
A decision structure can be used to perform menu selections
This can be accomplished through a case structure, series of nested if-then-else statements
A case structure is easier to follow the flow
A case structure will provide a case for each option in the menu, in addition to a default case

5. 11.1 Introduction to Menu-Driven Programs
Figure Flowchart for Program 11-1

6. 11.1 Introduction to Menu-Driven Programs
Validating the menu selection can be done before the case is processed, allowing for no need for a default
Display “Enter your selection”
Input menuSelection
//validation
While menuSelection < 1 OR menuSelection >3
Display “That is an invalid selection. Enter 1, 2 or 3”
End While

7. 11.2 Modularizing a Menu-Driven Program
Since a menu-driven program is capable of performing many tasks, it should be put into modules
A module should be written for each case that could be processed
The options would simply call modules
Allows for a clear flow of the program

8. 11.2 Modularizing a Menu-Driven Program
Figure Flowchart for the main module in Program 11-3

9. 11.3 Using a Loop to Repeat the Menu
Most menu-driven programs use a loop to repeatedly display the menu after a task is performed
This allows the user of the program to run another option without restarting the program
The menu can also contain on option for ending the program
Display “1. Convert inches to centimeters.”
Display “2. Convert feet to meters.”
Display “3. Convert miles to kilometers.”
Display “4. End the program.”

10. 11.3 Using a Loop to Repeat the Menu
Figure 11-7 Flowchart for the main module in Program 11-5

11. 11.4 Multiple-Level Menus
A multiple-level menu has a main menu and one or more submenus
Some complex programs require more than one menu
A programmer should consider breaking up long menus into multiple menus
This is essentially nested case structures

12. 11.4 Multiple-Level Menus Instead of this type of long menu
Process a sale
Process a return
Add a record to the inventory file
Search for a record in the inventory file
Modify a record in the inventory file
Delete a record in the inventory file
Print an inventory list report
Print a list of inventory items by cost
Print a list of inventory items by age
Print a list of inventory items by retail value

13. 11.4 Multiple-Level Menus Convert to multiple menus such as Main Menu
Process a Sale or a Return
Update the Inventory File
Print an Inventory Report
Exit the Program
Sales and Returns Menu
Process a Sale
Process a Return
Go Back to the Main Menu

14. 11.4 Multiple-Level Menus More menus Update Inventory File Menu
Add a Record
Search for a Record
Modify a Record
Delete a Record
Go Back to the Main Menu

15. 11.4 Multiple-Level Menus More menus Inventory Report Menu
Print an inventory list report
Print a list of inventory items by cost
Print a list of inventory items by age
Print a list of inventory items by retail value
Go Back to the Main Menu