public class Numbers
{
   /**
      Produces a string containing the numbers in an array,
      separated by commas, such as "1,4,9"
      @param values an array of integer values
      @return a string containing the array elements, separated by
      commas.
    */
   public String separateWithCommas(int[] values)
   {
      String str = "";
      for(int a : values){str += a + ",";}
      return (str.length() != 0) ? str.substring(0, str.length() - 1) : "";
   }
}