ArrayLists not adding values properly?

Question

Everything compiles, but when I print the size and the array elements, it indicates that not all of the values are added in because the size and the values would only be partial. Also, sometimes the sentinel value does not work( I have to enter it twice at times).What's wrong?

    import java.util.ArrayList;
    import java.util.Scanner;

    public class BowlingScoresArrayList{

    public static final int SENTINEL = -999;
    public static final int MIN=-1;
    public static void main (String [] Args) {

    ArrayList<Integer> bowlingScores = new ArrayList<Integer>(); 

    Scanner reader = new Scanner(System.in); 
    System.out.println("Enter your scores: ");

  do {
     bowlingScores.add(reader.nextInt());
  } while (reader.nextInt()!= SENTINEL); 

  System.out.println(bowlingScores);
  System.out.println(bowlingScores.size());

So I tried entering these values:

    Enter your scores: 
    1
    2
    2
    3
   -999
   -999

And it yields this:

    [1, 2, -999]
    3

and this includes the loop condition, since once you read the nextInt() the value obtained is used up. So read it into a **variable**, test that variable, and use it. — Hovercraft Full Of Eels, Jan 24 '16 at 03:48

score 2 · Answer 1 · answered Jan 24 '16 at 03:50

You're problem is, you're using two nextInt statements...

do {
   bowlingScores.add(reader.nextInt());
} while (reader.nextInt()!= SENTINEL);

So you're asking the user to provide input twice.

Instead, something like...

int in = SENTINEL;
do {
    in = reader.nextInt();
    if (in != SENTINEL) {
        bowlingScores.add(in);
    }
} while (in != SENTINEL);

would produce the desired results

ArrayLists not adding values properly?

1 Answers1