how to return 2 values upon calling a function

[David_Baratheon]

Hi everyone. How would i return two values each time I call a function? I have this program here, that is extracting 2 values from a text file every time a function is called, but I only seem to be able to return one value each time the function is called. I need to return column1 and column2 each time readingFunction() is called and they should be stored in readingsArray[loop] and temperatureArray[loop]. is it possible to return two values upon calling a function?

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <time.h>


float readingFunction(int loop);


int main(void)
{				
	int menu = 0;							 							  
	int readingsArray[10];
	float temperatureArray[10];
	int loop=0;


	do
	{
		printf("\n\n The sensor readings and their corresponding temperatures:\n\n");


		for(loop=0; loop < 10; ++loop) // Gives the user a set of readings
		{
			temperatureArray[loop] = readingFunction(loop); 
			printf("\nreading number %i is %i which is %f degree's", loop, temperatureArray[loop]);
		}


		
	return 0;




float readingFunction(void)
{ 
	FILE *fp;	
	int signalOutput;
	int flag=0;
	int column1;
	float column2;
	srand(time(NULL));	


	fp = fopen("LOOKUP.txt", "r");
	signalOutput = (int)(rand()%15);
	flag=0;
			


	while( ! flag ){
		fscanf(fp, "%i %f",&column1, &column2);
				
		if ( signalOutput <= column1 ) 
			{
					flag = 1;
					fclose(fp);			
			}	
		}


	return column1;
}

[dmh2000]

in C you can only return a single value from a function as the return value. however the return value can be a struct. so one way to do it would be to declare a struct with the 2 elements you need and return the entire struct.

struct X {
    float a;
    float b;
};

struct X function(void) {
   struct X r;
   r.a = 0.0f;
   r.b = 1.0f;
   return r;
}

...
struct X x;
x = function();
printf("%f %f\n",x.a,x.b);

the other way is to pass in pointers to the return values you want as arguments and set the values thru the pointers

void function(float *a,float *b)
{
    *a = 0.0;
    *b = 0.0;
   // no return statement needed
}

...
float x;
float y;

function(&x,&y);

printf("%f %f\n",x,y);