Question

I’m really puzzled as to how to call the function. UPDATED code in response to one or more answers. Current code and build errors are listed below.

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

//function prototypes
void signs(int x[], int size, int *negPtr, int *zeroPtr, int *posPtr);
double average(int x[], int size, int *greaterPtr);

int main()
{
//variable declarations
int zeroCounter, posCounter, negCounter, greaterThanAveCounter;
double ave;
int i;
int arr[63];
int size = 63;
int x[63], int size, int* negPtr, int* zeroPtr, int* posPtr, int* greaterPtr;

//seeding the random number generator function with the time
srand(time(NULL));

//filling the array with random numbers from the interval [-15, 40]
for(i=0; i<63; i++)
{
    arr[i] = rand()%(40-(-15)+1)+(-15);
}

//printing the array to the screen 9 elements per line
for(i=0; i<63; i++)
{
    if(i%9==0)
    {
        printf("\n");
    }
    printf("%5d",arr[i]);
}

//call function signs
signs (x, size, negPtr, zeroPtr, posPtr);

printf("\n\nThe number of elements that are negative is: %d\n",negCounter);
printf("The number of elements that are equal to zero is: %d\n",zeroCounter);
printf("The number of elements that are positive is: %d\n",posCounter);


//call function average
average(x, size, greaterPtr);

printf("The average of all the elements is: %.2f\n",ave);
printf("The number of elements that are greater than the average is: %d\n",greaterThanAveCounter);

return 0;
}



/***************************************************************************
signs:
This function finds the number of elements that are negative, positive and
equal to zero in an integer array. The number of elements that are negative,
positive and equal to zero are returned by 3 pointers that the function
receives.

Inputs
1. The integer array
2. The size of the aray
3. An integer pointer to the negative counter
4. An integer pointer to the zero counter
5. An integer pointer to the positive counter
***************************************************************************/
void signs(int x[], int size, int *negPtr, int *zeroPtr, int *posPtr)
{
int i;
for (i=0; i<size; i++)
{
    if(x[i]<0)
    {
        (*negPtr)++;
    }
    else if (x[i]==0)
    {
        (*zeroPtr)++;
    }
    else
    {
        (*posPtr)++;
    }
}
}



/***************************************************************************
average:
This function finds the average and the number of elements that are greater
than the average in an integer array. The function returns the value of the
average and returns the number of elements that are greater than the average
using a pointer that the function should receive.

Inputs
1. The integer array
2. The size of the aray
3. An integer pointer to the greater than average counter
***************************************************************************/
double average(int x[], int size, int *greaterPtr)
{
int i;
double ave;
int sum=0;

for (i=0; i<size; i++)
{
    sum+=x[i];
}

ave = (double)sum/size;

*greaterPtr = 0;
for (i=0; i<size; i++)
{
    if(x[i]>ave)
    {
        (*greaterPtr)++;
    }
}
return ave;
}

New Errors

• (32): error C2059: syntax error : ‘type’
• (35): warning C4244: ‘function’ : conversion from ‘time_t’ to
  ‘unsigned int’, possible loss of data

• (54): error C2065: ‘negPtr’ : undeclared identifier

• (54): warning C4047: ‘function’ : ‘int *’ differs in levels of
  indirection from ‘int’

• (54): warning C4024: ‘signs’ : different types for formal and
  actual parameter 3
• (54): error C2065: ‘zeroPtr’ : undeclared identifier

• (54): warning C4047: ‘function’ : ‘int *’ differs in levels of
  indirection from ‘int’

• (54): warning C4024: ‘signs’ : different types for formal and
  actual parameter 4

• (54): error C2065: ‘posPtr’ : undeclared identifier

• (54): warning C4047: ‘function’ : ‘int *’ differs in levels of
  indirection from ‘int’

• (54): warning C4024: ‘signs’ : different types for formal and actual
  parameter 5

• (62): error C2065: ‘greaterPtr’ : undeclared identifier

• (62): warning C4047: ‘function’ : ‘int *’ differs in levels of
  indirection from ‘int’

• (62): warning C4024: ‘average’ : different types for formal and
  actual parameter 3
• 1> 1>Build FAILED.

Answer 1

double average(int x[], int size, int *greaterPtr);

is how you declare a function. To call it, you need something like:

int a[10], b, *c;             // should also set these to sensible values.
double d = average (a, b, c);

---

In terms of your newly added error messages, I’ll help out with a few:

int x[63], int size, int* negPtr, int* zeroPtr, int* posPtr, int* greaterPtr;

This is not how you define multiple variables, it should be:

int x[63], size, *negPtr, *zeroPtr, *posPtr, *greaterPtr;

That’s probably the single cause of most of your current problems (I haven’t confirmed this, it’s more from a quick analysis).