Answer to Question #334953 in C# for kun

Question

a) Write a method PopulationTotal that accepts 2 positive values, namely the current

population and the growth rate . The method determines and returns the total population based on the current

population and growth rate.

b) Write a method Over180Million that accepts a positive value representing the population. The method determines whether the population is over 180 million people, and returns

a value of true if this is so, otherwise returns a value of false.

c) Write a program that requests the user for a year (you can assume the year will always be at

least 2000), the population of Brazil in that year and the annual

population growth rate (always as a real number in the range 0 – 1), and then uses the two

methods written above to determine and display the year in which Brazil’s population first

exceeded/exceeds 180 million people. The program must also display Brazil’s total population

in this year.

Answer 1

class Program
{
    static void Main()
    {
        int year = Read("Enter the year (2000+): ", 2000, 3000),
            population = Read("Enter the population of the year above: ", 0, int.MaxValue),
            growthRate = Read("Enter the growth rate: ");


        if (growthRate == 0)
        {
            Console.WriteLine("Growth rate too low!");
            return;
        }


        int total = population;
        while (!Over180Million(total))
        {
            total += PopulationTotal(total, growthRate);
            year++;
        }


        Console.WriteLine($"Population is over 180 million will be in {year}, with total population: {total}");
    }


   static int PopulationTotal(int population, int growthRate)
    {
        if (population * growthRate < 0)
        {
            Console.WriteLine("Values should be positive!");
            return 0;
        }


        return population + growthRate;
    }


    static bool Over180Million(int population)
    {
        if (population < 0)
        {
            Console.WriteLine("Values should be positive!");
            return false;
        }


        return population > 18 * 1_000_000;
    }


    static int Read(string message, int min = 0, int max = 100)
    {
        while (true)
        {
            Console.Write(message);
            if (int.TryParse(Console.ReadLine(), out int result) &&
                result >= min && result <= max)
                return result;
            Console.WriteLine("Incorrect value of mark, pleae, try again!");
        }
    }
}