---

Homework to practice ArrayList

---

• Do question 3 in the AP Computer Science A 2022 free-response questions:

  ---

• You can use the following Java classes to help you write the answers in BlueJ and test them:

  public class Review { private int rating; private String comment; /** Precondition: r >= 0 * c is not null. */ public Review( int r, String c ) { rating = r; comment = c; } public int getRating() { return rating; } public String getComment() { return comment; } }

  import java.util.ArrayList; public class ReviewAnalysis { /** All user reviews to be included in this analysis */ private Review[] allReviews; /** Initializes allReviews to contain all the Review objects to be analyzed */ public ReviewAnalysis( int n ) { allReviews = new Review[n]; } public double getAverageRating() { //write the code for Part A return 0; // Statement included so program can be compiled, change if necessary } public ArrayList collectComments() { //write the code for Part B return null; // Statement included so program can be compiled, change if necessary } /* Help method to make question work.... */ public void add( int x, Review r ) { allReviews[x] = r; } }

  ---

  Use this Java program to test your answer to question A:

  public class TestPartA { public static void main(String[] args) { ReviewAnalysis x = new ReviewAnalysis(5); x.add(1, new Review(5, "Great") ); x.add(0, new Review(4, "Good!") ); x.add(2, new Review(5, "Nice job!") ); x.add(3, new Review(1, "No! Bad") ); x.add(4, new Review(3, "") ); System.out.println( x.getAverageRating() ); } }

  The correct answer is: 3.6

  ---

  Use this Java program to test your answer to question B:

  public class TestPartB { public static void main(String[] args) { ReviewAnalysis x = new ReviewAnalysis(5); x.add(1, new Review(5, "Great") ); x.add(0, new Review(4, "Good!") ); x.add(2, new Review(5, "Nice job!") ); x.add(3, new Review(1, "No! Bad") ); x.add(4, new Review(3, "") ); System.out.println( x.collectComments() ); } }

  The correct answer is: [0-Good!, 2-Nice job!, 3-No! Bad.]

  Make sure you add the period at the end of the sentence if it was missing !!!