C Language, Newbie Function question

Newbie Function question

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<ba.. #1 / 3	Newbie Function question Im trying to jump from the perl world and have started teaching myself C. I'm running on a Gnu-Linux box and using GCC and would like to keep the code as portable as possible. My question relates to functions, and I hope is a simple one. If I understand correctly, a function is defined as such... int name(int x) so we have the return type, function name and then any data you want passed to the function. My question then, is can a function return more then one data type? For example, say I have a function that is doing my database talk for me and I want it to return a field entry, which is a string, and a value that would be say, just a type int. How can I return those types seperatly from one function without having to regex the hell out of a string, or can I? Jason www.cyborgworkshop.com ...and the geek shall inherit the earth...
Sun, 31 Oct 2004 09:08:02 GMT

Andreas K?h? #2 / 3	Newbie Function question Quote: > Im trying to jump from the perl world and have started > teaching myself C. I'm running on a Gnu-Linux box and using > GCC and would like to keep the code as portable as possible. > My question relates to functions, and I hope is a simple one. > If I understand correctly, a function is defined as such... > int name(int x) > so we have the return type, function name and then any data > you want passed to the function. My question then, is can a > function return more then one data type? For example, say > I have a function that is doing my database talk for me and > I want it to return a field entry, which is a string, and a > value that would be say, just a type int. How can I return > those types seperatly from one function without having to > regex the hell out of a string, or can I? A function can not return more than "one scalar" (using Perl-talk), which it really can't do in Perl either BTW. If you want to return a structure, define a struct that contains all the data that you want to return and then return an object of that structure type. typedef struct { int anint; double some, doubles; char str[40]; Quote: } mystruct; mystruct myfunc(int someval) { mystruct thestruct; strcpy(thestruct.str "Gedan daginn"); /* bladibladibla */ return thestruct; Quote: } -- Andreas K?h?ri -------------------------------------------------------------- Feed your daemons. www.netbsd.org
Sun, 31 Oct 2004 09:26:46 GMT

John Do #3 / 3	Newbie Function question Hi, Quote: > > My question then, is can a > > function return more then one data type? For example, say > > I have a function that is doing my database talk for me and > > I want it to return a field entry, which is a string, and a > > value that would be say, just a type int. How can I return > > those types seperatly from one function without having to > > regex the hell out of a string, or can I? Returning a string isn't as easy as it is in Perl. The only thing you can return is a pointer to a string (or, using Perl-talk again, a reference, which is not entirely the same). The memory required to store the string also has to be allocated somewhere in your program (remember to allocate enough space for the string including the termination 0). Quote: > A function can not return more than "one scalar" (using > Perl-talk), which it really can't do in Perl either BTW. If you > want to return a structure, define a struct that contains all > the data that you want to return and then return an object of > that structure type. A different solution is to pass storage pointers with the function call, e.g.: int myfunc(int in, int* out); myfunc can store information (in this case of type int) at the location the out pointer points to. Of course you can pass as many as you want of these (as long as you prototype your function as such). A third solution, which noone would recommend I hope, is using global variables. But pretend you never read that last line. Good luck with it, John
Sun, 31 Oct 2004 14:35:55 GMT

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