Convert string to double and the back?

[kezman]

Hey,
I'm writing a function to read a set of strings and doubles from an input file, and I now want to send them back to the main program. The function returns each value from the input file at a time, but I cant see how I can deal with returning two different types of data from one function.

I've got two ideas as to how I could do this, but no clue on how to implement them:

1) Convert all of the values (strings and numeric values) to doubles, return them to main and then convert the strings stored as a double back to a string type.

2) Return all of the values as their respective data type. Can a single function be used to more than one data type?

Unfortunately I am not sure how to do either of these, does anyone have any ideas?

Thanks alot,
Kieran

[tabstop]

And how is your calling function supposed to know what it's getting?

(You could define a struct with a string and a double in it, plus a code to say which one it has, and return that.)

But all that leads up to: how is your function that reads in supposed to know what it's going to get? Is there a format to the input file?

[cyberfish]

You can return by pointer parameters.

void func(int *return1, double *return2) {
     *return1 = 1;
     *return2 = 1.0;
}

int main() {
     int a;
     double b;
     func(&a, &b);
}

[kezman]

Thanks for the suggestions, I'll try the struct approach.

Yea, each value has a prefix to tell the function what to do with it.