CS241: Spring 2015 -- Lecture 3

1. Parameter Linkage and types of variables on p13...
2. Every non-Singleton class you write should have (well... almost every!).
   1. Accessors (to access the instance variables) - for encapsulation
   2. public String toString() - for debugging
   3. An initializing constructor - for ease of use
3. The Class maker app, which is not so easy to run due to "security enhancements". Fortunately, NetBeans does mostly the same thing (right-click/Insert code (or ^i)). Example: Exam, to keep track of student exam scores. String name;, and int score.
4. Recursive int[] seed(int), with a new (?) reserved word, final

       ...
       final int[] baseCase = {1,2};           // only 2 players, 1 plays 2
       ...
   
       int [] seed(int n) {  // this assumes n is a power of 2 >= 2
           if (n == 2) {  // base case?
               return baseCase;
           return expand(seed(n/2));  // if not, recurse with n/2
       }
               
       int[] expand(int[] small) {     // fill in their opponents to double the size
           int[] returnMe = new int[small.length*2];  // twice as big
           ...
           return returnMe;
       }
       ...
       display(seed(8));   // test it on n=8
          
               

5. 2-dimensional arrays
   1. declaration

      int[][] sq = new int[N][N];
                          

   2. iterating over

              for (int row = 0; row < N; row++) {
                  for (int col = 0; col < N; col++) {
                      ...sq[row][col]...
                  }//inner for
              }//outer for

   3. display
      1. to output -- making it line up
      2. to a TextArea -- making it line up
   4. Example: magic squares (with clicks to highlight/switch rows/cols)