// Objects should encapsulate state (fields) and expose behavior (methods)
// Note that we did not comment any of these methods! We will talk in Thursdays
// section and Friday's lectures about commenting in depth!
public class ArrayIntList {
   // Absolutely remember to keep all fields private. We don't want
   // a client to have to "go into the circuitry" of our object to make
   // it work.
   private int[] elementData;
   private int size;
   
   public ArrayIntList() {
      // We fairly arbitrarily chose the internal array to be able to 
      // hold up to 10 elements
      elementData = new int[10];
   }
   
   public void add(int value) {
      elementData[size] = value;
      size++;
   }
   
   // Note that after we made the size field private, we still wanted a client
   // to be able to ask what the current size is. We can let them see the value
   // but not change it with this getter method, size
   public int size() {
      return size;
   }
   
   public int get(int index) {
      return elementData[index];
   }
   
   public int indexOf(int value) {
      // One bug we had was looping to "elementData.length". Remember
      // that the client only "sees" the first "size" elements. Checking
      // the entire array would result in the client "seeing" values that
      // they aren't aware of
      for (int i = 0; i < size; i++) {
         if (elementData[i] == value) {
            return i;
         }
      }
      return -1;
   }
}