Returning a Struct from a function

paulmcco (86)
Okay, we discussed this before but I'm trying to return a struct from a function...(within a header file) Here is the struct:

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struct Pairs
{
int pairCard1; //Numeric value of 1st set of matching variables
int pairCard2; //Numeric value of 2nd set of matching variables
}input[2];


here is the function:

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int PairCardReturn(int card1, int card2, int flop1, int flop2, int flop3)
{
	int numbs[5]= {card1, card2, flop1, flop2, flop3}, n = 5, j=1;
	for (int i = 0; (i < n - 1); i++)
        {			
			for (j = i + 1; (j < n) && m<2; j++)
			{
				if (numbs[i] == numbs[j]) return numbs[i]; //First numeric value from 2 matching variables			
			}					
        }	
	return 0;	
}


I need the function above to apply the numeric value of 2 matching variables to the struct Pairs (pairCard1) and and second numeric value from a 2nd set of matching variables to the struct Pairs (pairCard2)...Any ideas would be appreciated...
LB (13399)
Why are you making two Pairs structs? All you need to do is change the function return type from int to Pairs, and inside the unction make a Pairs object and set the data and return it.
paulmcco (86)
Are you saying the function should loook like this?

struct Pairs{
int pairCard1;
int pairCard2;
}input[2];

Pairs ReturnStruct()
{
Pairs input;
int numbs[5]= {1, 2, 1, 2, 4}, n = 5, j=1, m = 0;
for (int i = 0; (i < n - 1); i++)
{
for (j = i + 1; (j < n) && m<2; j++)
{
if (numbs[i] == numbs[j]) input[m] = numbs[i]; //First numeric value from 2 matching variables
}
}

return Pairs;
}


What should I return? Pairs? input?
closed account (zwA4jE8b)
just set the return type to whatever struct you need and in your function return it.
paulmcco (86)
Here is the code in its entirety, could you tell me what's wrong...?

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//-----Function
struct Pairs{
int pairCard1;
int pairCard2;
}input[2];

Pairs ReturnStruct()
{
	Pairs input;
        int numbs[5]= {1, 2, 1, 2, 4}, n = 5, j=1, m = 0;
        for (int i = 0; (i < n - 1); i++)
        {                       
                        for (j = i + 1; (j < n) && m<2; j++)
                        {
                                if (numbs[i] == numbs[j]) input[m] = numbs[i]; //First numeric value from 2 matching variables                      
                        }                                       
        }       

}

//----------Main Program

int main()
{
	ReturnStruct();
	return 0;
}
closed account (zwA4jE8b)
you are not returning anything. only void functions do not return.

return 'your struct'; //at the end of the function

Also, you never increase m. so input[m] will always be on index 0.
Last edited on
LB (13399)
If you're going to do it like that you might as well put all the code from ReturnStruct() into main() and not even use a function in the first place.
Last edited on
paulmcco (86)
okay, understood! so how do I access the information from the main program..? If you add the 'return input' code to the ReturnStruct function, the program does nothing...how do I access the struct from the main program?
LB (13399)
By assigning it to a struct in the main program...?
closed account (zwA4jE8b)
when you set up your function to return a struct then in main you just declare a struct and assign it to your function.
closed account (zwA4jE8b)
example of assigning a function to a variable

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#include <iostream>

int intfunction()
{
   return 3;
}

int main()
{
   int a = intfunction();
   std::cout << a;
   return 0;
}
Last edited on
paulmcco (86)
for the sake of eliminating problems, I put all the code into the main program...it looks like this:

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using namespace std;

struct Pairs{
int pairCard1;
int pairCard2;
};

struct pairCard{
int pairCard1;
int pairCard2;
};


pairCard ReturnStruct(struct Pairs mystruct);
int main()
{
	
	Pairs input;
	pairCard output;
	output = ReturnStruct(input);
	
	return 0;
}

pairCard ReturnStruct()
{
	pairCard answer;
	answer.pairCard1 = 3;
	answer.pairCard2 = 4;
	
	return answer;
}


This code returns an error: conversion from 'Pairs" to non-scalar type 'PairCard' requested...Is this error caused because I am asking the program to return two values?
Last edited on
closed account (zwA4jE8b)
you do not need two structs that contain the same data...

in main

Pairs input = ReturnStruct();

thats it. you declare input as a datatype Pairs and assign it to be of that type.

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using namespace std;

struct Pairs{
int pairCard1;
int pairCard2;
};

Pairs ReturnStruct();

int main()
{
	
	Pairs inmain = ReturnStruct();
              cin.get();  //To hold the console open
	return 0;
}

Pairs ReturnStruct()
{
	Pairs infunc;
	infunc.pairCard1 = 3;
	infunc.pairCard2 = 4;
	
	return infunc;
}


*fixed.
Last edited on
paulmcco (86)
Got it thanks a lot to all!
Last edited on
closed account (zwA4jE8b)
try the fixed code. I edited my last post.


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#include <iostream>

using namespace std;

struct Pairs{
int pairCard1;
int pairCard2;
};

Pairs ReturnStruct();

int main()
{
	
	Pairs inmain = ReturnStruct();
	cout << inmain.pairCard1 << " " << inmain.pairCard2;
    cin.get();  //To hold the console open
	return 0;
}

Pairs ReturnStruct()
{
	Pairs infunc;
	infunc.pairCard1 = 3;
	infunc.pairCard2 = 4;
	
	return infunc;
}


paulmcco (86)
I added ReturnStruct after struct Pairs declaration...same diff thanks!

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struct Pairs{
int pairCard1;
int pairCard2;
}ReturnStruct();
paulmcco (86)
I put the Pairs ReturnStruct() function in a header file but when I run the program, now, parse and syntax errors occur...any ideas why?
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