GVSU CS 162 Lecture-Module #07: Debugging

CS 162 Lecture-Module #07:
Debugging

while this lecture-material uses an old IDE called NetBeans, debugging is similar in other integrated development~environments such as BlueJ

"debugging" means correcting your program
considering error-messages or other behavior you observe
when you repeatedly try to compile, execute it

this term arose when some computers not electronic (transistor) wiring
but electromechanical
and the programmer/operator Grace Murray Hopper found a moth jamming one relay:
original bug:

address the first error-message when compiling

to start debugging, set a breakpoint (see below) and then start execution as usual
(if program already in the middle of being executed, first conclude that)

depiction of debugging:

: line of operational code at the beginning of which you want execution to pause

non-operational code: comment, declaration, solitary brace, ...
operational code is code that actually does something

multiple ways to breakpoint:
- click in the thin column at left of target line of code
- when cursor is on line:
- menu: Debug: New BreakPoint...
may need to successfully compile changed class before setting breakpoints

panel is supposed to show values of variables

means: execute 1 statement and then pause execution
icon:

shortcut: key
further variations presented subsequently

primitive debugging:
really can be useful sometimes

summary of this lecture-module

basics of debugging: