protected void removeRange(int fromIndex,int toIndex){
  modCount++;
  int numMoved=elementCount - toIndex;
  System.arraycopy(elementData,toIndex,elementData,fromIndex,numMoved);
  int newElementCount=elementCount - (toIndex - fromIndex);
  while (elementCount != newElementCount)   elementData[--elementCount]=null;
}

protected void removeRange ( int fromIndex , int toIndex ) { modCount ++ ; int numMoved = elementCount - toIndex ; System . arraycopy ( elementData , toIndex , elementData , fromIndex , numMoved ) ; int newElementCount = elementCount - ( toIndex - fromIndex ) ; while ( elementCount != newElementCount ) elementData [ -- elementCount ] = null ; }
removes from this list all of the elements whose index is between fromindex , inclusive and toindex , exclusive . shifts any succeeding elements to the left ( reduces their index ) . this call shortens the arraylist by ( toindex - fromindex ) elements . ( if toindex = = fromindex , this operation has no effect . )
