CSE115: Introduction to Computer Science I

1. CSE115: Introduction to Computer Science I Dr. Carl Alphonce 219 Bell Hall 645-4739 alphonce@buffalo.edu

2. Phones off Signs out

3. Announcements • Advice • take notes in lecture • don’t rely only on slides • REVIEW notes regularly • bring notes to recitation • Web-CAT • we’re tweaking it • don’t worry if you get e-mail about regrading

4. Agenda • Brief review • Unified Modeling Language (UML) • Methods in general

5. BRIEF REVIEW

6. Object • class instantiation • created by ‘new’ + constructor • representation stored on heap

7. Reference • an address • value of ‘new’ expression

8. Variable • name • location • type • value • scope • lifetime • local variable • instance variable

9. Expression • examples of expressions • ‘new’ expression • variable expression (on RHS of assignment) example1.Terrarium t1; example1.Terrarium t2; t1 = new example1.Terrarium(); t2 = t1;

10. package • organizational mechanism • each class belongs to a package

11. class • “blueprint” of an object

12. constructor • used by new to initialize a new object

13. scope • static property of variable • part of program text where a variable declaration holds

14. lifetime • runtime property of variable • period of time during which variable exists in memory

15. UML • Unified Modeling Language • industry standard • Class diagrams

16. UML • Unified Modeling Language • express design without reference to an implementation language • For example

17. Binary Class Relationships:directional • binary  two classes are involved • source class has code modification • target class does not • composition • source: WHOLE • target: PART • in diagram: • line decoration is on source/WHOLE • show only detail that’s needed/desired

18. package cse115; public class Dog { public Dog() { } } package cse115; public class Tail { public Tail() { } }

19. package cse115; public class Dog { private Tail _tail; public Dog() { _tail = new Tail(); } } package cse115; public class Tail { public Tail() { } }