Thread: Passing Values From Functions

Oh thanks i forgot to add that part into the code.

I'm still having trouble though passing the value of the average.

post code and error msg.

Error:'avg_function' undefined; assuming extern returning int

Code:

#include <stdio.h>
#include <stdlib.h>
int num_fahr_temps (void);
double avg_function (double array[], int numValues)
void input_fahr_temps (double array [], int numValues);
void output_temps (double array [], int numValues);
void avg_high_low (double array [], int numValues);
void abo_bel_equ (double array [], int numValues, double avg);

int main (void)

{
    double array [25], avg;
    int numValues;
 
    numValues = num_fahr_temps ();
    avg = avg_function ();
 
    input_fahr_temps (array, numValues); 
    output_temps (array, numValues);
    avg_high_low (array, numValues);
    abo_bel_equ (array, numValues, avg);
 
    return 0;    
}
 
int num_fahr_temps (void)
{
    int numValues;
 
    printf ("\n        CIS 231 - Assignment 3 - Brian Avrit \n\n");
 
    printf ("How many fahrenheit tempetures would you like to enter (1-25) : ");
    scanf ("%i", &numValues);
 
    while ((numValues < 1 ) || (numValues > 25))
    {
        printf ("\nValue is out of range, please re-enter another value : ");
        scanf ("%i", &numValues);
    }
 
    return numValues;
}
 
void input_fahr_temps (double array[], int numValues)
{
    int i;
 
    for (i = 0; i < numValues; i++)
    {
        printf ("\nEnter value for fahrenheit %i: ", i);
        scanf ("%lf", &array[i]);
        while ((array[i] < -175.0) || (array[i] > 175.0)) 
        {
            printf ("\nValue is out of range,  please re-enter: ");
            scanf ("%lf", &array[i]);
         }
    }    
}
 
void output_temps (double array[], int numValues)
{
    int i;
 
    printf ("Fahr\n");
 
    for (i = 0; i <numValues; i++)
        printf ("%.1lf\n", array [i]);
}
 
void avg_high_low (double array [], int numValues)
{
    int i;
    double avg, high, low, sum = 0;
     
    high = array[0];
    low = array[0];
 
    for (i = 0; i < numValues; i++)
        sum = sum + array [i];
        avg = sum / numValues;
 
    for (i = 0; i < numValues; i++)
        if (array[i] < low) 
            low = array[i]; 
    for (i = 0; i < numValues; i++)
        if (array[i] > high)
            high = array[i];
 
    printf ("\nAverage: %.1lf\n", avg);
    printf ("\nHigh: %.1lf\n", high);
    printf ("\nLow: %.1lf\n", low);
}
 
double avg_function (double array[], int numValues){

    int i;
    double avg;
 
    for (i = 0; i < numValues; i++)
        sum = sum + array [i];
        avg = sum / numValues;
 
    return avg;
}
 
void abo_bel_equ (double array[], int numValues, double avg)
{
    int i, abo = 0, bel = 0, equ = 0;
 
    for (i = 0; i < numValues; i++)
        if (array[i] > avg) 
            abo++;
            printf ("\nAbove Average: %i \n", abo); 
             
    for (i = 0; i < numValues; i++)
        if (array[i] < avg) 
            bel++;
            printf ("Below to Average: %i \n",bel); 
 
    for (i = 0; i < numValues; i++)
        if (array[i] == avg) 
            equ++;
            printf ("Equal to Average: %i \n", equ); 
}

double avg_function (double array[], int numValues)


Missing the semi-colon in the proto-type.

This is where I get confused.

To return the value of the numValues I had to do the function "int num_temps (void)". I'm assuming if I wanted to return the value of the average I would do the function "double avg_function (void)" not a "double avg_function (double array[], int numValues)" function. But how does the "double avg_function (void)" know to use the values inputted from the array?

Sorry if that's confusing, but thats the best way I could describe it.

Maybe you should try and write the function and post it. Where are the values supposed to come from?

Sorry I'm a little confused on what function I should try. Do you mean the "double avg_function (void)" function? Because if I do that then the function doesn't know the values of the array.

If I do (void) avg_function (double array [], int numValues); I get an error from this line of code "avg = avg_function ()" in the main function. The error states that "there are too few arguements in function call".