Thread: segmentation: function called with multiple outputs?

I have a function of the form:

Code:

float function(string[],i) {
/*multiple operations, each with some output...and I know this works, as I have already ran it outside of this function and debugged it by printing each output*/

switch(i) {                /* i equals 1,2, or 3, and selects the output of the function*/
  case 1: return (x); /* x is a float */
  break;
  case 2: return (n); /* n is an integer*/
  break;
  case 3: return (c); /*c is a char
  break;
  default: printf("Inavlid request\n");
}
} /*end function*/

int main () {

/*input string and i*/

float answer=function(string,i);
printf("Answer=%f\n",answer);

return 0;
}

I'm guessing the fault is because I have declared function as a float, but in certain cases, the function is trying to return an int or char. (mind you, I still get this error when I select i=1, returning the float variable). I have tried declaring function as void, but got some compile-time errors.

Is this problem likely to be causing my segmentation error or will it be something else?

How can I ammend this?

thanks

Ok, thats what I thought...I must have tried to access a string[n] with an invalid string number,n, I'll have to double check everything. On another note, is this a valid method of returning different values from a function? If the values are different types, as in mine, what do I declare the function as? void?

Use a union.

Depends on exactly how much is happening in the different cases, if it's only a couple lines of code. Somewhat pointless to make functions for all of them (unless you plan to do a lot of expansion later on).

I thought about making different functions, and using a function pointer, but the 'operations' I have used in this code are quite long (There is about 100 lines of code in place of that first comment), and so it would be nice to just be able to have the one, and select the output. I suppose actually for my purpose I could convert the char and int to float values, and keep track of this when calling the function, so that is one possibility. I will also look at unions, and also try it with different functions just to see if it works. Thanks.

If each one of those case statements is going to have 100 lines of code, you need to write separate functions for increased readibility and maintainability. Otherwise you will just have one extremely bloated function.

HI both, I've solved both of these problems now....after debugging for ages, I noticed I hadn't used '&' on one of the scanf functions lol, and as for the function problem, I ended up using two seperate functions and calling them as appropriate...it turned out after some thought, that I didn't have to include all 100 lines of code in each function after all, since there were bits that were and weren't needed for each one. It is still pretty lengthy, and I might make them into a header file, but at least I'm confident that it is optimized well (I'm sure there is no shorter way to do what I wanted...well, with my limited knowledge of c at least ). Thank you very much!