BMI calculation and Menu logic [closed]

Question

I am totally new to programming and have been racking my head around something that I know is so basic. I am not one to learn online so this is proving to be more difficult.

So I am needing to create a C# console app that has a menu where you have three options that include an 'exit'. So far I have only been able to run option 1 and 2 separately. When I view membership rates I can only choose option 1. Then when I tried to place coding for both membership and BMI calculation together I can still only run the membership!

Below is my code:

using System;

namespace BMITEST1MILLION
{
    class Program
    {
        static void Main(string[] args)

        {
            Console.WriteLine("Kiaora! Welcome to City Gym. Please select one of the following options:");
            Console.WriteLine("1.) View Our Membership Rates");
            Console.WriteLine("2.) Calculate My BMI");
            Console.WriteLine("3.) Exit");

            int num = Int32.Parse(Console.ReadLine());

            if (num == 1) ////condition.run if user main menu input is option 1 
            {
                Console.Clear();//clears previous screen

                Console.WriteLine("Which membership type would you like to view?"); //prompting user input
                Console.WriteLine("1.) Basic");
                Console.WriteLine("2.) Regular");
                Console.WriteLine("3.) Premium");


                int num1 = Int32.Parse(Console.ReadLine()); //declare if option 1 chosen
                if (num1 == 1) //condition. run if user input for membership type is 1
                {
                    Console.Clear(); //clears previous screen
                    Console.WriteLine("Our Basic Membership Rate is $10 per week or $40 per month");
                }


                int num2 = Int32.Parse(Console.ReadLine()); //declare if option 2 chosen
                if (num2 == 2) ; //condition. run if user input for membership type is 2
                {
                    Console.Clear(); //clears previous screen
                    Console.WriteLine("Our Regular Membership Rate is $15 per week or $60 per month");
                }

                int num3 = Int32.Parse(Console.ReadLine()); //declare if option 3 chosen
                if (num3 == 3) //condition. run if user input for membership type is 3

                {
                    Console.Clear(); //clears previous screen
                    Console.WriteLine("Our Premium Membership Rate is $20 per week or $80 per month");
                }


                if (num == 2)//condition.run if user main menu input is option 2 (BMI Calcuation)

                    //BMI calculation

                    Console.Write("Enter you height in metres (m):"); //ask user to input their height in metres
                double userHeight = Convert.ToDouble(Console.ReadLine()); // convert string to a double

                Console.Write("Enter you weight in kilograms (kg):"); //ask user to input their wedight in kilograms
                double userWeight = Convert.ToDouble(Console.ReadLine()); // convert string to a double

                double BMI = userWeight / (userHeight * userHeight); //method to calculate BMI based on user input weight and height
                Console.WriteLine("Your BMI is " + Math.Round(BMI, 2)); //print BMI result to screen. Round result to two decimals.

                if (BMI <= 18.5)//condition
                    Console.WriteLine("You are underweight.");

                else
                    if (BMI <= 25)//condition
                    Console.WriteLine("Your weight is normal.");

                else
                    if (BMI <= 30)//condition
                    Console.WriteLine("You are overweight.");

                else //if BMI is greater then 30
                    Console.WriteLine("You are obese.");

                Console.ReadKey();

            }//end of bmi calcuation

        }//main menu
    }//end of class
}//end of namespace

Answer 1

I recommend use of the do and switch-case:

do {
  switch(option) {
    case 1: //do something
    break;
 
    case 2: //do something
    break;

    case 3: //exit
    break;

    default: // wrong option
    break;
  }
}while(option != 3);

Regards!

Answer 2

It seems like the structure of your main if statements is a little off. In order to execute either option 1 or option 2, it would be as

if(num == 1){
  ...
}
if(num == 2){
  ...
}

but you have

if(num == 1){
  ...
  if(num == 2)
}

Maybe this is what you meant by placing the code together? In this case, since you don't have braces following the if(num == 2) it will only apply to the line immeditately below it, ie the line that prints "Enter you height in metres (m):". However, since it only checks this condition if num already equals 1 (because it's nested in the num == 1 block), that line will never execute, so it skips that line and continues to double userHeight = Convert.ToDouble(Console.ReadLine());. Hope this helps!