CSIS 110 – Lecture 9
Quiz Results
mean 20.1
stdev 5
median 22
max 24
Distribution (after EC):
<15: 1 15-17: 2 17.5 – 19.5: 3 20 – 22: 1 22.5+: 5
Reading Assignment: Section 4.11. Potentially confusing. Read before Monday, and
again after lecture.
Last time: this keyword
Debugger
Open the mail project again. Create a server and two mail clients: One for Fred and one
for Bill. Send message from Fred to Bill, but don’t read it yet.
I’m going to be using a tool called a Debugger so we can see what is happens when Bill
tries to print his next email.
Set BP on first line of printNextMailItem. Then call this method for Bill. What
happens?
A new window comes up – this is the debugger window. It has some parts:
- Buttons at the bottom
- Three windows on the right for different types of variables
oDon’t worry about static vars – we don’t know what they are yet, and this
class doesn’t have any
oInstance variables – we can see the values of the instance variables as they
exist at this particular statement
oLocal variables – there aren’t any YET, because it hasn’t been created. We
stopped the program execution before the statement is executed.
So, with the debugger, we can stop the execution of the program to inspect the values of
the variables.
We can also use it to step through the program slowly.
Single Stepping
When we are stopped in the debugger, we can use the Step button to execute one
statement. [Do it].
