// Introduction to Software Testing
// Authors: Paul Ammann & Jeff Offutt
// Chapter 1, section 1.2, page 12

class numZero
{

public static int numZero (int[] arr)
{  // Effects: If arr is null throw NullPointerException
   // else return the number of occurrences of in arr
   int count = 0;

   // As example in the book points out, this loop should start at 0.
   for (int i = 1; i < arr.length; i++)
   {
      if (arr[i] == 0)
      {
         count++;
      }
   }
   return count;
}

public static void main (String []argv)
{  // Driver method for numZero
   // Read an array from standard input, call numZero()
   int []inArr = new int [argv.length];
   if (argv.length == 0)
   {
      System.out.println ("Usage: java numZero v1 [v2] [v3] ... ");
      return;
   }

   for (int i = 0; i< argv.length; i++)
   {
      try
      {
         inArr [i] = Integer.parseInt (argv[i]);
      }
      catch (NumberFormatException e)
      {
         System.out.println ("Entry must be a integer, using 1.");
         inArr [i] = 1;
      }
   }

   System.out.println ("Number of zeros is: " + numZero (inArr));
}

}