Hacking: The Art of Exploitation, 2nd Edition

Control Structures

Without control structures, a program would just be a series of instructions executed in sequential order. This is fine for very simple programs, but most programs, like the driving directions example, aren't that simple. The driving directions included statements like, Continue on Main Street until you see a church on your right and If the street is blocked because of construction…. These statements are known as control structures, and they change the flow of the program's execution from a simple sequential order to a more complex and more useful flow.

If-Then-Else

In the case of our driving directions, Main Street could be under construction. If it is, a special set of instructions needs to address that situation. Otherwise, ...