L19AdvancedArrayTopics.java

public class L19AdvancedArrayTopics{
   public static void main(String[] args){
      Circle[] cArr = new Circle[4];
      //ILLEGAL - not instantiated System.out.println( cArr[0].circumference() );
      for(int i = 0; i < cArr.length; i++){
         cArr[i] = new Circle(3);
      }
      /* BAD WAY to instantiate elements
      Circle c = new Circle(3);
      for(int i = 0; i < cArr.length; i++){
         cArr[i] = c;
      }
      */

      //Two different references to the same array
      Circle[] aka = cArr;
      aka[1].setRadius(99);
      System.out.println( cArr[1].getRadius() );

      //Enhanced Circle for loop
      for( Circle c : cArr ){
         System.out.println( c );
      }

      //For loops are read only
      int[] x = {1,2,3,4};
      for( int i : x ){
         i = -99;
      }
      System.out.println( x[0] );

      // UNLESS an array of objects is changed using methods
      for( Circle c : cArr ){
         c.setRadius(999);
      }
      System.out.println( cArr[2] );
   }
}