Enhanced for Loops

• A for loop can be used to iterate (loop through) the vaules of a list.

• The basic syntax is:

  for (Class var : list)

• The first part is a declaration of var, where it is the data type of an element in the list.

• Each time through the loop, the variable var is set to the next value in the list.

• Note: because the variable is set to the value in the list, this type of loop cannot be used to change the list, but can only be used to change the objects in the list.

• Let's draw this code to demonstrate:

      Point points[] = { new Point(), new Point(15,300) };
      int i;
  
      System.out.println("**Original list");
  
      for (i = 0; i < points.length; i++)
          System.out.println(i + " : " + points[i]);
  
      System.out.println();
      System.out.println("**Enhanced for");
      for (Point p:points)
      {
          System.out.println(p);
          p = new Point(100, 300);
      }
  
      System.out.println();
      System.out.println("**Standard for");
      for (i = 0; i < points.length; i++)
      {
          System.out.println(i + " : " + points[i]);
          points[i] = new Point(100, 300);
      }
  
      System.out.println();
      System.out.println("**Final list");
      for (i = 0; i < points.length; i++)
          System.out.println(i + " : " + points[i]);
  }