C++ value return trouble.

[dataDude]

I think this message belongs in this category, but I'm guessing. Here goes...

I'm currently working on a C++ program (just started, still within first 60 lines) and it's doing something really weird. I don't know what the heck's going on here, but at some point an integer variable is being passed to another function that does nothing more than take one piece of input from the user and then returns it, but when it gets returned, the value in the variable is off.... way off. The input is supposed to be between 1 and 13, but right after the variable is set, the value returned is something like -1204396852. To me it's as if the computer is saying "you don't mean that, let's try this one."

In a nutshell, the functions look like this:

#include

using namespace std;

int select(int myOption)
{
cout << "Enter option: ";
cin >> myOption;

return myOption;
}

int main()
{
int opt;

option(opt);

cout << opt;

return 0;
}

Anyone have an idea?

P.S.: I'm on a Linux system working with the built in compiler.

[adsta]

The reason the output is strange is because the variable isn't being assigned to the value of the function. It basically equals null (depending on the compiler).

It should be:

opt = select()

I'm not quite sure why you are passing the opt variable into the function. It isn't going to do anything. So rather than having the function like select(int myOpt), just have select(). But if you do need to do that, it's not the cause of the error, so no need to worry.

Remember the returned value of the function is retrieved by the actual function itself, hence why you need opt = select() in your main function. That means "The variable opt equals the return value of the function select()".

Something like this should work:

int select()
{
int myOption;
cout << "Enter option: ";
cin >> myOption;
return myOption;
}

int main()
{
int opt;
opt = select();
cout << opt;
return 0;
}

Hope that helps

[alfie2]

it's well and good to return a value from a function name, but when
more than one value is needed to return from a function then passing by reference is used.

you can use something like:

void select(int &myOption1, int &myOption2)
{
cout << "Enter option 1: ";
cin >> myOption1;
cout << "Enter option 2: ";
cin >> myOption2;

}

int main()
{
int opt1,opt2;

option(opt1,opt2);

cout << opt1 << opt2;

return 0;
}

[dataDude]

Right after I asked, I figured out the opt = option(var) solution (though I didn't know I could leave the "var" part out). Overall, didn't know it could be done the way you guys told it. I just figured you kept the variable with you throughout the program (meaning I thought you had to pass the variable and return it). Shoot, that works. Thanks. I have another question concerning the program as well, but I'll post separately.