1. C And C Based IO

2. C C = portable assembly language Developed 1972 w/Unix – Systems focus

3. C++ C++ introduced new features to C – Objects Collection of data with associated behaviors – Templates – References – …

4. Current Relation C and C++ separate languages, separate governing bodies C++ often adopts changes in C, not always

5. Why Two Languages Tools C++ provides give us – Ways to program in different styles – Ways to build tighter abstractions – Ways to make things more/less efficient C gives us – Simplicity – De facto standard for linking code

6. C++ Bootstrapped on C C++ provides own versions of common c libraries

7. Libraries C++ and C libraries are subtly different

8. C IO No cin/cout objects – Use functions: C++ LibraryC Library

9. Printf Printf prints formatted strings: As many extra parameters as format codes

10. Printf Format Codes:

11. Examples Basic formatting

12. Printf Formatting Format Codes: – %numbercode : min width -number : left justify

13. Printf Formatting Format Codes: – %0numbercode Pad with 0s – %+numbercode Print + for positive – % numbercode : Space for +

14. Printf Formatting For floating point – %.2f any number of chars, 2 decimal places – Default behavior : %.6 assume e = 2.718281828:

15. Printf Formatting Examples

16. Scanf Scanf reads formatted strings into variables

17. Scanf Scanf reads information into variables:

18. Addresses Two meanings for & int& x – C++ only : variable is a reference to another int variable &x (x already exists) – C/C++ : address of x

19. Scanf Scanf reads information into variables: – Wants address of anything it is reading in

20. Scanf Type mismatch = weird errors:

21. Scanf Can scan from formatted strings: Space in format string = unlimited whitespace Skip unlimited white space before reading

22. Why Do I Care If you are writing C C functions may make life easier: C printf("%10.3f", &x); C++ cout << fixed << setprecision(3) << setw(10) << x;