functions to return 2 variables?

i'm trying to have a function return 2 values to 2 separate variables. i know the idea is for a function to only do 1 specific thing, and thats pretty much what my functions are doing. the only difference is, depending on user input, 1 of 2 different variables will be modified. SO, at the end of this function, i have it return 2 variables - 1 has been modified, 1 is the same as when the function began.

i COULD go back and make 2 functions, which may be what i have to do, but it'd be really convenient if there was a way to be able to return multiple variables.

this is what i have tried thus far - this is similar to the format in other programming languages (mainly math-oriented ones) so i thought it might work, but no luck:

[int, int] functionname(variable1, variable2, variable3)

then, in the main program, to call it, i put:

[mainvariable1, mainvariable2]=functionname(variable1, variable2, variable3);

and within the function i put:

return(mainvariable1, mainvariable2);

hoping that would do the trick to return 2 variables. it didn't.

any help?

Well, either you can return one value and write the other one through a pointer to a variable defined in main, write both through pointers, or return a pointer to an array of two variables defined in the function, or simply return a pointer.

1) int function( int firstval, int *secondval )
{
*secondval = ...;
return firstval;
}

...

variable = function( variable, &variable2 );
printf( "%d %d", variable, variable2 );

2) typedef int ( *ptr_to_ar )[2];
ptr_to_ar function( int firstval, int secondval )
{
static int intar[2];
ptr_to_ar ptr = &intar;
return ptr_to_ar;
}

3) int *function( )
{
int *ptr = malloc( x * sizeof( int ) );
return ptr;
}

You can approach this several different ways, the pointer way:

Code:

---

void function ( int *varOne, int *varTwo );
/* The call */
function ( foo, bar );

---

The non-pointer return one way:

Code:

---

int function ( int varOne, int VarTwo ) {
  if ( something for varOne ) {
    /* Set the value */
    return varOne;
  }
  else if ( something for varTwo ) {
    /* Set the value */
    return varTwo;
  else
    return /* error value goes here */
}

---

Or you can just wrap both variables in a stuct and return that.

There are many ways, but generally if you need to return two values your design is flawed and should be looked at.

-Prelude

In C a function can only return one variable, so you'll have to use duplicate functions or pointers.

Another thing you could do is defining a structure which contains both values. Fill the structure in the function and return it. Or pass a structure to the function and let it be filled.

You could also use an array, which can be filled or returned by the function.

Shiro, I like your interesting solutions!