Question

I am trying to convert a JavaScript switch to a C# one.

I am getting error Error 3 Cannot implicitly convert type 'bool' to 'int'

        switch (numero)
        {
            case (numero > -1 && numero < 16):
                rtn = list1[numero] + " " + str2;
                if (primerDigito != 1)
                {
                    rtn += "s";
                }
                break;
            case (numero > 15 && numero < 30):
                if (numero != 20)
                {
                    rtn = list2[primerDigito] + list1[segundoDigito];
                }
                else
                {
                    rtn = "veinte";
                }
                rtn += " " + str2 + "s";
                break;
            case (numero > 29 && numero < 100):
                rtn = list2[primerDigito] + "nta";
                if (segundoDigito != 0)
                {
                    rtn += " y " + list1[segundoDigito];
                }
                rtn += " " + str2 + "s";
                break;
            case 100:
                rtn = "cien " + str2 + "s";
                break;
            default:
                rtn = "número invalido";
        }

Is there a work around for this?

Note: I really MUST use switch-case (and not if-elses)

Answer 1

You cannot do this: a switch statement can only use single values, not ranges for the cases.

You need an if/else tree instead. Something in the form of:

if(numero > -1 && numero < 16) {
 rtn = list1[numero] + " " + str2;
 if (primerDigito != 1)
 {
  rtn += "s";
 }
} else if(numero > 15 && numero < 30) {
 // logic in second block
} else if...

Note that if you’re absolutely, totally committed to using a switch, you would have to enumerate all of the cases (but this is such an egregious sin against software engineering that I can’t even believe I’m writing it out – do not do this, it’s just an example of how switch statements work):

switch(numero)
{
 case 0:
 case 1:
 case 2:
 case 3:
 case 4:
 case 5:
 case 6:
 case 7:
 case 8:
 case 9:
 case 10:
 case 11:
 case 12:
 case 13:
 case 14:
 case 15:
  rtn = list1[numero] + " " + str2;
  if (primerDigito != 1)
  {
   rtn += "s";
  }
  break;
 case 16:
 ...
 case 28:
 case 29:
  // second logic block
  break;
 ...
}

If I saw this in my codebase, though, I would be baffled and angry.