1. Coding Constructs considered Violations of Structured Programming
Black Magic
Coding Constructs considered
Violations of
Structured Programming

2. Background
Programming Languages before the 1980’s allowed program flow to “bounce around” anywhere the programmer wanted.

3. RESULT: “Spaghetti Code”
Background
RESULT: “Spaghetti Code”

4. Background “Spaghetti Code” very difficult to Debug
almost impossible to Maintain
not Reusable

5. Solution: Structured Programming
Background
Solution: Structured Programming
Organize and encapsulate code into clear, maintainable segments, each with one Entry and Exit point.

6. Structured Programming: Example 1
Background
Structured Programming: Example 1

7. Structured Programming: Example 2
Background
Structured Programming: Example 2

8. Many battles were fought in the 1960’s-80’s
Background
Many battles were fought in the 1960’s-80’s

9. Background Structured Programming Won.
A major result: the standard use of the Pascal language to teach new programmers.
Pascal enforces concepts of Structured Prog.

10. C++ There are statements in C (and so C++) that violate
Structured Programming
to some degree

11. return from anywhere in a function:
Actually a major violation of SS, but commonly used by C++ programmers.

12. return from anywhere in a function:
int main() {
...
if (something)
return 1;
return 0; }

13. continue jump to the end of a loop somewhat common in C++

14. while (something) { //loop control
continue
while (something) { //loop control
...
if (something)
// jump to beginning of loop
continue; }

15. a little more common in C++
break
exit a control block
(loop, switch, if, etc.)
a little more common in C++

16. C++ break; while (something) { //loop control ... if (something)
break; // exit the loop }
// jump to here

17. C++ “The word that SHALL NOT be uttered”
banned by most C++ programmers
unrestricted use in C
major restrictions in C++

18. The word that SHALL NOT be uttered: GOTO
C++
The word that SHALL NOT be uttered:
GOTO

19. CS 215
The following should NOT be used in any CS 215 programs (labs, projects, tests)
continue
break
(except in a switch)
goto

20. The following is allowed: return in the middle of a function
CS 215
The following is allowed:
return
in the middle of a function

21. After 215 Once you’ve finished CS 215 and “Earned Your Stripes”
you may be allowed to use these statements, but...
Best to ask the Instructor

22. Test Nothing from this set of slides will be on the tests...
except NOT using the “banned” statements.