import java.util.ArrayList;
/* On the exam you will have a copy of the following program, 
 * with examples of ArrayList and array declarations, if-statements,
 * and while, for, and for-each loops.
 */
/* A class to maintain an arbitrarily long list of notes.
 * @author David J. Barnes and Michael Kolling. */
public class Notebook
{
    // Storage for an arbitrary number of notes.
    private ArrayList<String> notes;
    private String[] notes2;    // what an array declaration would look like

    /* Perform any initialization that is required for the notebook. */
    public Notebook() {
        notes = new ArrayList();
        notes2 = new String[20];    // fixed size array; not used below
    }

    /* Store a new note into the notebook.    */
    public void storeNote(String note) {
        notes.add(note);
    }

    /* @return The number of notes currently in the notebook.     */
    public int numberOfNotes() {
        return notes.size();
    }

    /* Remove a note from the notebook if it exists, given its number.   */
    public void removeNote(int noteNumber) {
        if(noteNumber < 0) {
            // This is not a valid note number, so do nothing.
        } else if(noteNumber < numberOfNotes()) {
            // This is a valid note number.
            notes.remove(noteNumber);
        } else {
            // This is not a valid note number, so do nothing.
        }
    }

    /* List all notes in the notebook; while loop version     */
    public void listNotes() {
        int index = 0;
        while(index < notes.size()) {
            System.out.println(notes.get(index));
            index++;        // or index += 1
        }
    }

    /* List all notes in the notebook; for loop version     */
    public void listNotes2() {
        int index ;
        for(index = 0; index < notes.size(); index++) {
            System.out.println(notes.get(index));
        }
    }

    /* List all notes in the notebook; for-each loop version     */
    public void listNotes3() {
        for ( String note : notes ) {
            System.out.println(note);
        }
    }
}