Starting Out with Programming Logic & Design Second Edition by Tony Gaddis

Chapter 11:Menu-Driven Programs Starting Out with Programming Logic & Design Second Edition by Tony Gaddis

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

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 11-1 A menu

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

11.1 Introduction to Menu-Driven Programs Figure 11-2 Flowchart for Program 11-1

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” Input menuSelection End While

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

11.2 Modularizing a Menu-Driven Program Figure 11-5 Flowchart for the main module in Program 11-3

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.”

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

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

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

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

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

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

Starting Out with Programming Logic & Design Second Edition by Tony Gaddis