Lecture 27

1. COP3502: Introduction to CIS I Lecture 27

2. Pset 0 3% • Pset 1 5% • Pset2 7% • Pset 3 15% • Pset 4 20% • Pset 5 20 % • Exam 1 10% • Exam 2 10% • Labs 10%

3. lab 5 cipher decoder

4. problem set 4 “interactive text adventure”

5. reading a file • Open the file • BufferedReaderbr = new BufferedReader(new FileReader(filename)); • Read the file line by line • String line = br.readLine(); • Close the file • br.close();

6. writing a file • Open the file • PrintWriter pw = new PrintWriter(new FileWriter(filename)); • Print the file line by line • pw.println(text); • Close the file • pw.close();

7. catching exceptions try { //some code } catch (Exception ex) { //hande the exception in some way }

8. java collections containers used to store, retrieve, andmanipulate aggregate data generic

9. java collections containers used to store, retrieve, andmanipulate aggregate data generic ex: arrays

10. java collections containers used to store, retrieve, andmanipulate aggregate data generic ex: arrays, ArrayList

11. Collection

12. List interface add() get() remove() size() contains()

13. Collection List

14. Collection List ArrayList

15. Collection List LinkedList ArrayList

16. Collection Set List Queue HashSet SortedSet LinkedList PriorityQueue NavigableSet ArrayList LinkedHashSet TreeSet

17. Map

18. maps set of key/value pairs

19. examples of maps dictionary phone book

20. dictionary key: word to look up value: definition access values in a map by looking up the key

21. dictionary key: word to look up value: definition access values in a map by looking up the key maps Strings to Strings

22. Map HashMap

23. Map HashMap SortedMap TreeMap

24. HashMap new HashMap<K, V>() K – type of key V – type of value

25. HashMap methods put(key, value)

26. HashMap methods value = get(key)

27. HashMap methods remove(key)

28. HashMap methods contains(key)