edX-FSharp-Module2-Assignment.fs

open System

let rec getPeopleCount() : int =
    Console.Write("How many people? ")
    let countinput = Console.ReadLine()
    let canparse, count = Int32.TryParse(countinput)
    if canparse then
        if count <= 0 then 
            Console.WriteLine("** Please enter a number, greater than 0 **")
            getPeopleCount()
        else
            count
    else
        Console.WriteLine("** Please enter a number, greater than 0 **")
        getPeopleCount()

let getPersonsName(index : int) : string =
    Console.Write("{0}:\tPlease enter person's name: ", index)
    Console.ReadLine()

let rec getPersonsAge(name : string) : int = 
    Console.Write("\tHow old is this {0}: ", name)
    let ageinput = Console.ReadLine()
    let canparse, age = Int32.TryParse(ageinput)
    if canparse then
        if age <= 0 then
            Console.WriteLine("\t** Please enter an age greater than 0 **")
            getPersonsAge name
        else
            age
    else
        Console.WriteLine("\t** Please enter an age greater than 0 **")
        getPersonsAge name

[<EntryPoint>]
let main argv = 
    let count = getPeopleCount()

    for index = 1 to count do        
        let name = getPersonsName index
        let age = getPersonsAge name

        if age >= 20 then
            Console.WriteLine("\t{0} is no longer a teenager.\n", name)
        elif age > 12 then
            Console.WriteLine("\t{0} is a teenager.\n", name)
        else
            Console.WriteLine("\t{0} is a child.\n", name)
            
    Console.ReadKey()

    0