Using a letter as a case in a switch-case code

I'm trying to write a switch-case code that converts degrees and I ask for user input of F or C for determining which temperature to convert to. How do I get the code to accept F or C in the case? I know it has to do something with converting the letter to a string but I can't for the life of me find how to do it anywhere. This is my code right now:

temp = input('Input a temperature: ');
unit = input('Do you want to convert to Fahrenheit or Celsius (F/C): ');
switch unit
    case F
        temp=temp*1.8+32;
    x=['The temperature is ',num2str(temp), ' degrees fahrenheit'];
    disp(x)
    case C
        temp=(temp-32)*5/9;
    y=['The temperature is ',num2str(temp), ' degrees celsius']
    disp(y)
end

Answer 1

[Stephen23]

Always use the 's' option with input, like this:

 temp = str2double(input('Input a temperature: ','s'));
 unit = input('Do you want to convert to Fahrenheit or Celsius (F/C): ','s');
 switch unit
    case 'F'
       ...
    case 'C'
       ...
 end

As the documentation states, the 's' options returns a string. You should always use the 's' option (even if you are getting a numeric value) because it is safer and more robust.

[Adam]

Also note the other fundamental change in Stephen's code than the original that he didn't explicitly mention:

'F' and 'C' need to be strings in the switch statement, not just

case F

etc