Error Checking

The method assumes that the user will supply correct data for the parameters. But users do not always follow the rules. The following call will not work:

operate.printRange( ar1, 1, 10 );

There are only eight elements of ar1. If you asked to print elements 1 through 10 you would see:

19 1 5 -1 27 19 5 java.lang.ArrayIndexOutOfBoundsException

When the method tries to access the non-existing 8th element, the program throws an exception. Here is the method, again, with some new blanks:

class ArrayOps
{
  . . .

  // print elements start through end
  void printRange ( int[] x, int start, int end )
  {
    for ( int index=start; index <= end && ___________ && ___________; index++  )
      System.out.print( x[index] + " " );
    System.out.println();
  }

}

The new version of the method makes sure that index is zero or greater, and is less than the length of the array.