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From: Thomas8675309 AT yahoo DOT com (Tom)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: C/C++ switch statement question
Date: 1 Dec 2003 07:59:08 -0800
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cmad_x AT yahoo DOT com (Chris Mantoulidis) wrote:

> in my c++ program i use the switch statement with a string parameter.
> for example
> 
> string s;
> cin >> s;
> switch (s)
> {
> .......
> }
> 
> but i get an error saying "switch quantity not an integer"... probably
> the switch needs an integer parameter and probably that's the same
> with C (and a char * in the example).

True enough.

> so... there is no way that i can use switch for a string?
> 
> i have to use IF-ELSE???

No, assuming you are using C++ (rather than "C/C++", whatever that
is), you don't have to use if-else if you don't want to.  You could
use a std::map, for example.  If you're wedded to using a switch
statement, you could do something like the following:

#include <map>
#include <string>
#include <iostream>

int main()
{
  using namespace std;
  enum CommandNums { Error = 0, Stop, Go, Reset, Quit };
  map<string, int> commands;
  commands["stop"] = Stop;
  commands["go"] = Go;
  commands["reset"] = Reset;
  commands["quit"] = Quit;
  bool keepGoing = true;
  while (keepGoing) {
    cout << "Enter your command, quit to end: ";
    string s;
    cin >> s;
    switch (commands[s]) {
      case Stop:
        cout << "You entered 'stop'" << endl;
        break;
      case Go:
        cout << "You entered 'go'" << endl;
        break;
      case Reset:
        cout << "You entered 'reset'" << endl ;
        break;
      case Quit:
        cout << "Goodbye" << endl;
        keepGoing = false;
        break;
      case Error:
        cout << "I didn't understand that." << endl;
    }
  }
}

A more sophisticated way would be to ditch the switch statement
altogether and instead map each command to a function pointer or
functor that would execute the code corresponding to the command.

Again, you're likely to get more helpful info posting to
comp.lang.c++.moderated or comp.lang.c++ than posting here.

Best regards,

Tom