code: public static int indexOf (int[] values, int value)
      {
          int count = (values == null) ? 0 : values.length;
          for (int ii = 0; ii < count; ii++) {
              if (values[ii] == value) {
                  return ii;
              }
          }
          return -1;
      }
docs: Looks for an element that is equal to the supplied value and returns its index in the array.
  
  @return the index of the first matching value if one was found, 1 otherwise.