Thread: How to write a function and calling it in the main using a global variable array?

I'm a college student very new to programming. I'm having some troubles with this specific program.

The program should be able to store 500 integer values (temperatures) in a global array. The program has to contain the specific functions:

• A function that finds the average of all temperatures stored
• A function that finds the average of the last 5 recorded temperatures. If there are less than 5 temperatures recorded, return the average of all recorded temperatures.
• A function that records a new temperature. It must check if there is still space in the array.
• A function that prints the number of temperatures recorded
• A function that prints all the temperatures recorded

Here is my current program. I only need help writing ONE of the functions. I want to learn how to write and call them myself with some guidance. Thanks all.

Code:

#include <stdio.h>
#define maxsz 500


int temp[maxsz];


float avgtemp ()
{
    
}
float avgtemp5()
{
}
int addtemp ()
{


}
int numtemp()
{
}
int alltemp()
{
}
int main(void)
{


    char option;


    printf("Please select an option:\n");
    printf("(A) Computed average of all temperatures\n");
    printf("(B) Compute the average of the last five temperatures\n");
    printf("(C) Add new Temperatures\n");
    printf("(D) Print the number of temperatures recorded\n");
    printf("(E) Print the temperatures recorded\n");
    printf("(F) Exit the program\n");
    scanf(" %c", &option);
    
    switch (option)
    {
        case 'A': avgtemp();
        
        case 'B': avgtemp5();
            
        case 'C': addtemp();
        
        case 'D': numtemp();
            
        case 'E': alltemp();
            
        case 'F': return 0;
    }


    return 0;
}

How are you supposed to populate the array? The questions imply that the array may hold any number of temperature values (up to the max).

For development purposes, I'd suggest you print a string in each function saying which function you're in. This will help you uncover a problem in "main()". These strings can be removed as you move forward.

Build your program gradually, testing along the way: A development process