switch(num)
{
  case 1:
    if(bla)
    {
      Machwas();
    }
    break;
  case 2:
  case 3:
    switch(str)
    {
      case "a":
        if(blubb)
        {
           goto case 1; // Cannot convert type 'int' to 'string'
        }
        goto case "b";
      case "b":
        Machwasanderes();
        break;
    }
  default:
  break;
}

---
Woher soll ich wissen, was ich denke, bevor ich h?re, was ich sage?