Chapter 3, Problem 53E

Explanation of Solution

Given: The better-ticket-machine project.

To find: The steps to use the debugger in the method named insertMoney present in the class TicketMachine and apply test conditions that executes if-statement as well as else-statement.

Solution:

In order to set the breakpoint in the first line of insertMoney method, it is necessary to open the editor of class TicketMachine.

An editor window will appear on screen.

Now, create an object of TicketMachine class and set the cost to 500.

Now, invoke the method named insertMoney and enter the amount as 1000.

When the user clicks ok button, a new debugger window will pop-out on the screen.

Now, click the Step command in the debugger window.

The line of execution has now been changed from the first line to the second line. It has now been entered inside the if-statement.

Again, click the Step command in the debugger window. The value of the variable named balance present in the section of instance variables has now been changed from 0 to 1000 and the line of execution has now been moved to the last line of the insertMoney method...