ArrayList Loop Patterns

Process All Items

 
public void printReviews()
{
   // Print each review using its toString method.
   for ( MovieReview review : reviewList )
   {
      System.out.println(review);
   }
}

public void printReviews()
{
   // Print each review using its toString method.
   for ( int i = 0; i < reviewList.size(); i++ )
   {
      MovieReview review = reviewList.get(i);
      System.out.println(review);
        // or ...println(reviewList.get(i));
   }
}

public void printReviewers()
{
   // Print the reviewer for each review.
   for ( MovieReview review : reviewList )
   {
      System.out.println(review.getReviewer());
   }
}

public void printReviewers()
{
   // Print the reviewer for each review.
   for ( int i = 0; i < reviewList.size(); i++ )
   {
      MovieReview review = reviewList.get(i);
      String reviewer = review.getReviewer();
        // or reviewer = reviewList.get(i).getReviewer();
      System.out.println(reviewer);
   }
}

Sum All Items

 
int sum = 0;     // total number stars earned
for ( MovieReview review : reviewList )
{
    // Add rating to total number stars earned.
    sum += review.getRating();
}
System.out.printf("Sum: " + sum);

int sum = 0;     // total number stars earned
for ( int i = 0; i < reviewList.size(); i++ )
{
    // Add rating to total number stars earned.
    MovieReview review = reviewList.get(i);
    sum += review.getRating();
}
System.out.printf("Sum: " + sum);

Calculate Average

 
public double getAvgRating()
{
   double sum = 0.0;   // total stars earned
   double avg = 0.0;   // average stars earned

   // Calculate total number stars earned
   for ( MovieReview review : reviewList )
   {
      sum += review.getRating();
   }

   // Calculate average stars earned
   avg = sum / reviewList.size();
   return avg;
}

public double getAvgRating()
{
   double sum = 0.0;   // total stars earned
   double avg = 0.0;   // average stars earned

   // Calculate total number stars earned
   for ( int i = 0; i < reviewList.size(); i++ )
   {
      MovieReview review = reviewList.get(i);
      sum += review.getRating();
   }

   // Calculate average stars earned
   avg = sum / reviewList.size();
   return avg;
}
Alyce Brady, Kalamazoo College