CPSC 170 PreLab 2: Arrays

1. Write a method boolean findCD(CD cd) for the CDCollection class on p. 389-392 of the text. This method should take a CD object and return true if that CD is in the collection, false otherwise. You don't want look through the array any longer than you have to - think carefully about what kind of loop to use!

   Important: Assume that you have already added a public boolean equals(CD cd) method to the CD class (p. 393) that returns true if two CDs are considered equal.

   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

2. We talked about accessing rows and columns in a two dimensional array. If the array is a square, we can also talk about its diagonals. The main diagonal goes from the upper left corner to the lower right corner, and the other diagonal goes from the lower left corner to the upper right. So in the square below, the elements of the main diagonal from left to right are 1 6 11 16 and the elements of the other diagonal are 13 10 7 4.

   1  2  3  4
   5  6  7  8
   9  10 11 12
   13 14 15 16
   

   1. Write code that prints the elements of the main diagonal, one per line, for a two-dimensional array a.

      
      
      
      
      
      

   2. Write code that prints the elements of the other diagonal, one per line, for a two-dimensional array a.