Java 'ArrayList' Pseudocode ....

protected int modCount = 0;

ArrayList(int initialSize)

        IF  initialSize<0  THEN
                       Throw exception "Invalid Size"
       else
             arrayElement= new Object[initialSize];
        

ArrayList() 

  Call ArrayList(defaultSize); // default-size is 10

ArrayList(Collection<? extends E> C)
     arrayElement = C.toArray();
     size = arrayElement.length;
     IF arrayElement.getClass() != Object[].class THEN
                 arrayElement = Arrays.copyOf(arrayElement, size, Object[].class);

ensureCapacity(int newCapacity) 

   modCount++
   oldCapacity  = arrayElement.length;
    IF newCapacity > oldCapacity THEN
         Object[] oldData = arrayElement;
         newCap = (oldCap *3)/2 +1;
         IF newCap < newCapacity THEN
                   newCap=newCapacity;

         ENDIF
    END IF
  arrayElement =Arrays.copyOf(arrayElement, newCap); // My own implementation is at the end.

add(E data)
    ensureCapacity(size + 1);  // Increments modCount!!
    elementData[size++] = data;


add(int index, E element)
 IF index > size OR  index < 0 THEN
        throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
 ENDIF
 ensureCapacity(size+1);  // Increments modCount!!
 System.arraycopy(elementData, index, elementData, index + 1, size - index); //shifting the right hand side elements by 1.
 elementData[index] = element;
 size++;

RangeCheck(int index)
   IF index >= size THEN
        throw new IndexOutOfBoundsException( "Index: "+index+", Size: "+size);

 remove(int index)

  RangeCheck(index)
  modCount++;   // modification count
  Object oldVal = elementData.get(index);
  int numMoved = size - index - 1;

addAll(Collection<? extends E> c)

Object[] a = c.toArray();
length = a.length;
ensureCapacity(size + numNew);
System.arraycopy(a, 0, elementData, size, numNew);
 size = size + numNew;
return numNew != 0;




  ........... to be continued (will add other details later)