How do I set a value in one method and then return that value to another method?

Question

I need some help. If I understand this right, the value of "int F" gets sent to "FtoC" converted and then returned to the MenuSelect1 method. Now I want to return or save the value "int C" has after its been converted to the MenuSelect2 method? I have tried everything I can think of, but I just get errors. (I have reset the code to original state now where MenuSelect1 and 2 är void). Whats an easy way to solve this? Thank you.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


  public static class SecondClass {


  public static int FtoC(int fahrenheit)
  {
    int C = ((fahrenheit - 32) * 5) / 9;
    return C;
  }

  
  public static void MenuSelect1()
  {
    while (true)
    {
      int F = 0;
      Console.Write("\nType how many degrees Fahrenheit you want: ");

      try
      {
        F = Convert.ToInt32(Console.ReadLine());
      }
      
      catch (Exception e)
      {
        Console.ForegroundColor = ConsoleColor.DarkRed;
        Console.WriteLine("ERROR!");
        Console.ForegroundColor = ConsoleColor.White;
      }

      int C = SecondClass.FtoC(F);

      if (C < 80 || C > 87)
      {
        Console.WriteLine("Try a different temperature.");
      }
      else
      {
        Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
        break;
      }
    }
    Console.ReadKey();
  }

   
  public static void MenuSelect2()
  {
    Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
    Console.Write("Temperature: {0}");
    Console.ReadKey();
  }
    

}

Answer 1

You could also save the value of C as a property / field in your class. Here is an example of saving it as a field called _celcius:

using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


  public static class SecondClass {

  private static int _celcius = 0;  // <--- Your field

  public static int FtoC(int fahrenheit)
  {
    int C = ((fahrenheit - 32) * 5) / 9;
    return C;
  }

  
  public static void MenuSelect1()
  {
    while (true)
    {
      int F = 0;
      Console.Write("\nType how many degrees Fahrenheit you want: ");

      try
      {
        F = Convert.ToInt32(Console.ReadLine());
      }
      
      catch (Exception e)
      {
        Console.ForegroundColor = ConsoleColor.DarkRed;
        Console.WriteLine("ERROR!");
        Console.ForegroundColor = ConsoleColor.White;
      }

      _celcius = SecondClass.FtoC(F);   // <--- Assign field here

      if (_celcius  < 80 || _celcius  > 87)
      {
        Console.WriteLine("Try a different temperature.");
      }
      else
      {
        Console.WriteLine(_celcius + "°C is perfect. Start the sauna and enjoy!");
        break;
      }
    }
    Console.ReadKey();
  }

   
  public static void MenuSelect2()
  {
    Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
    Console.Write("Temperature: {0}", _celcius); // <--- Use your field here
    Console.ReadKey();
  }
    

}```