Generics and the ArrayList Class - Absolute Java - page 772

Display 14.2 A for-each Loop Used with an ArrayList (part 2 of 2)

19 System.out.print("More items for the list? ");
20 answer = keyboard.nextLine();
21 if (!(answer.equalsIgnoreCase("yes")))
22 done = true ;
23 }

24 System.out.println("The list contains:");
25 for (String entry : toDoList)
26 System.out.println(entry);
27 }
28 }

Sample Dialogue

Enter list entries, when prompted.
Input an entry:
Practice Dancing.
More items for the list? yes
Input an entry:
Buy tickets.
More items for the list? yes
Input an entry:
Pack clothes.
More items for the list? no
The list contains:
Practice Dancing.
Buy tickets.
Pack clothes.

Self-Test Exercises

8. Suppose numberList is an object of the class ArrayList<Double> . Give code
that will output all the elements in numberList to the screen.
9. Write a class for sorting strings into lexicographic order that follows the outline
of the class SelectionSort in Display 6.11 of Chapter 6 . Your definition,
however, will use an ArrayList of the class ArrayList<String> , rather than
an array of elements of type double . For words, lexicographic order reduces to
alphabetic order if all the words are in either all lowercase or all uppercase letters.
You can compare two strings to see which is lexicographically first by using
the String method compareTo . For strings s1 and s2 , s1.compareTo(s2)
returns a negative number if s1 is lexicographically before s2 , returns 0 if s1
equals s2 , and returns a positive number if s1 is lexicographically after s2 . Call