// Introduction to Software Testing
// Authors: Paul Ammann & Jeff Offutt
// Chapter 1, page 13
// Can be run from command line
// See CountPositveTest.java for JUnit tests

public class CountPositive
{
  /** 
   * Counts positive elements in array
   *
   * @param x array to search
   * @return number of positive elements in x
   * @throws NullPointerException if x is null
   */
   public static int countPositive (int[] x)
   {
      int count = 0;
   
      for (int i=0; i < x.length; i++)
      {
         if (x[i] >= 0)
         {
            count++;
         }
      }
      return count;
   }
      // test:  x=[-4, 2, 0, 2]             
      //        Expected = 2
   
   public static void main (String []argv)
   {  // Driver method for countPositive
      // Read an array from standard input, call countPositive()
      int []inArr = new int [argv.length];
      if (argv.length == 0)
      {
         System.out.println ("Usage: java CountPositive 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 positive numbers is: " + countPositive (inArr));
   }
}