Question about returning values.

[logana]

Below is a basic example of returning a value. My question; is there a way to send multiple values back. Say X = 2 and Y = 5. Could I send back both using the return. And then on the Main use X and Y where I need it. Or is it not possible or too complicated to be of practical use?


void ball();
int stone();

int main() {
ball();
int pebble = stone();
cout << endl << " " << pebble << endl;
return 0;
}
// function definitions below:
void ball() {
cout << " This is a basic return function " << endl;
}
int stone() {
int y = 5;
int x = 10; // Can we send a y value back if the function was altered?
return (x);
// Does a return, just deal with one value?

[ashertech]

I think you can do this at the end of your function:

return x;
return y;

then use them where appropriate in the main function

[jlb]

// Does a return, just deal with one value?

Yes a function can only "return" one value. However you can pass values into the function by reference to allow changes made to the variables in the function to be reflected in the calling function.

#include <iostream>

using namespace std;

void stone(int& x, int& y)
{
   x = 10;
   y = 2;
}

int main()
{
    int x = 0;
    int y = 0;

    stone(x, y);

    cout << x << " : " << y << endl;
}

[TheIdeasMan]

@ashertech

Completely wrong !

To make variables available in an outer scope, pass those variable to the function by reference:

void stone(int& x, int& y) { // pass by ref with &
  int y = 5;
  int x = 10; // 
}

[Flaze07]

Maybe you can use array...


I discouraged it though

[coder777]

You can return only a single value. But you can/probably should create a struct and return an instance of this:

struct position
{
  int x;
  int y;
};

void ball();
position stone();

int main() {
ball();
position pebble = stone();
cout << endl << "x: " << pebble.x << "y: " << pebble.y << endl;
return 0;
}
// function definitions below:
void ball() {
cout << " This is a basic return function " << endl;
}
position stone() {
  position result;
  result.y = 5;
  result.x = 10;
return result;

You may also use tuple to return multiple values:

http://www.cplusplus.com/reference/tuple/tuple/?kw=tuple

[logana]

Ashertech- I will give that a go now and see if it works.

I've also learned in programming, or concise programming, to return a sum, rather than type it out separately. These little things, help a lot in reducing the bulk.

What I am trying to-do is tie up the loose ends and understand all the possibilities with Returning. I think we have done that now.

I'm going to be surprised when I see real programs at the end of my studies, to see what the code looks like in the real world. I'm a long way off from that.

[logana]

Ashertech. The compiler only reads the first Return and ignore the second. There are no errors showing. I think the Return option is a one entry one time delivery service. Does anyone else agree?




return x;
return y;

[AbstractionAnon]

logana wrote:

Ashertech- I will give that a go now and see if it works.

As pointed out by TheIdeasMan consecutive return statements will not work.
Execution will reach the first return statement and exit the function. The second return statement will never be reached.