//  Meanvalue.swift  Copyright (c) Kari Laitinen

//  http://www.naturalprogramming.com

//  2014-09-28  File created.
//  2015-10-17  Last modification.

//  This program demonstrates the repeat-while loop, which is similar
//  to the do-while loop in other programming languages.

import Foundation

// The type of integer_from_keyboard is Int! because the conversion
// from String may fail.

var  integer_from_keyboard : Int!  =  0
var  number_of_integers_given  = -1
var  mean_value                =  0.0  // The type of mean_value becomes
                                       // Double as we assign a Double value
var  sum_of_integers           =  0

print( "\n This program calculates the mean value of"
    +  "\n the integers you enter from the keyboard."
    +  "\n Please, start entering numbers. The program"
    +  "\n stops when you enter a zero. \n" )

repeat
{
   print( "   Enter an integer: ", terminator: "" )
   integer_from_keyboard  =  Int( readLine()! )

   number_of_integers_given  += 1
   sum_of_integers  =  sum_of_integers + integer_from_keyboard
}
  while  integer_from_keyboard  !=  0

if number_of_integers_given  >  0 
{
   mean_value  =  Double( sum_of_integers ) /
                  Double( number_of_integers_given )
}

print( String( format: "\n The mean value is: %f \n\n", mean_value ) )