CPSC 170 PreLab 1: Arrays

1. Tell whether each of the following will produce a compile-time error, a runtime error, or no error. If there is an error, explain why; if no error, tell what the code will print.

   a)   String[] names;
        System.out.println(names[0]);
   
   
   b)   String[] names;
        names = new String[10];
        System.out.println(names[5]);
   
   
   c)   String[] names;
        names = new String[10];
        System.out.println(names[5].length());
   
   
   d)   String[] names;
        names = new String[10];
        for (int i=0; i<10; i++)
           names[i] = "joe" + i;
        System.out.println(names[5]);
   
   
   e)   String[] names;
        names = new String[10];
        for (int i=0; i<10; i++)
           names[i] = "joe" + i;
        System.out.println(names[5].length());
   
   
   

2. Write a method boolean findCD(String title) for the CDCollection class on p. 337-338 of the text. This method should take a string and return true if a CD with that title is in the collection, false otherwise. Important: Assume that you have already added a public String getTitle() method to the CD class (p. 340) that returns the title for a CD.

   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

3. Consider the array below:

   5

   8

   9

   11

   12

   14

   15

   20

   22

   25

   Use binary search to search for values

   1. 15
   2. 16
   in this array. For each search, show the values of lo, hi, and mid at each step.