Thread: Function that returns string

I would like to have something like this in my blackjack program :

Code:

string suit(int cardvalue) {

    if (cardvalue<13)
        return "Spades";
    else if (cardvalue < 26)
       return "Diamonds";
}

And so on and so forth.

But right now, all I can do is have it return 'S' (Spades), 'D'
(Diamonds), etc etc (The one letter being a character, as it will let
the function return a character).

Any help is appreciated.

If we're in C (checks board...), then there is no such thing as string. There is such a thing as const char *, though, which is what "Spades" and "Diamonds" are.

That is c++. In C you woudnt return a string, instead you pass a pointer to a "char array" that the text will be copied to.

Code:

void suit(int cardValue, char* out, size_t outLen)
{
    if (cardValue < 13)
        strncpy(out, "Spades", outLen);
    else if (cardvalue < 26)
        strncpy(out, "Diamonds", outLen);
    else *out = 0; //Null terminate
}

int main(int argc, char* argv[])
{
    char textBuffer[1024];
    suit(4, textBuffer, sizeof(textBuffer));
    printf("&#37;s\n", textBuffer);    //Should print "Spades"
    return 0;
}

Originally Posted by 39ster

That is c++. In C you woudnt return a string, instead you pass a pointer to a "char array" that the text will be copied to.

Or, of course, allocate a buffer, put the string there, and return a pointer to the buffer. The caller is responsible for freeing it. This is often the only option if the calling code has no way of telling a priori how big a buffer will be necessary.

Never mind, I got it:

Code:

char *get_suit (int val)
{
   int suit;
   static char *suits[] = {"spades", "diamonds", "clubs", "hearts", "wtf"};

   if (val < 13) {
       suit = 0;
   } else if (val < 26) {
      suit = 1;
   } else if (val < 39) {
      suit = 2;
   } else if (val < 53) {
      suit = 3;
   } else {
      suit = 4;  // should never happen
   }

   return suits[suit];

Originally Posted by tabstop

If we're in C (checks board...), then there is no such thing as string. There is such a thing as const char *, though, which is what "Spades" and "Diamonds" are.

technically, they are char[7] and char[9].

Code:

char *get_suit(int val)
{
  static char *suit[] = {"spades","diamonds","clubs","hearts"};
  return suit[val / 13];
}

It's better because will execute faster than a sequence of if-then expressions.
The compiler will also generate less object code.

I don't believe in adding range checking to each and every function - if you're passing in out-of-range values, your calling code is buggy!

const qualifier? Only for variables.
And most compilers don't enforce it anyway. Of documentation value only (perhaps).