Functions and Subroutines

1. Why to use subroutines?
2. Subroutines
3. Variable number of parameters
4. Recursive subroutines: factorial
5. Recursive subroutines: Fibonacci
6. Sort using a function
7. Return a list
8. Return several elements
9. Error handling with eval - files
10. Error handling with eval - two calls
11. Exercise: Subroutines
12. Exercise: Number guessing in sub
13. Solution: Number guessing in sub