Question

I’m learning a bit C and i’m doing an exercise where i use structures and functions to collect employee infos and just print them out.
I’m declaring the functions and the struct in the header since i need them in both of the other files.

//employee.h

int addEmployee(void);
int printEmployee(int i);

struct employeelist 
{
    char last [20];
    char first[20];
    int pnumber;
    int salary;
};

The “core” file is executing the both functions. The first function asks for the number of employees and gives a value back for the second function where the information is collected and stored. There are no errors and i’ve checked the code several times.

//employee.c

#include "employee.h"
#include <stdio.h>
#include <ctype.h>
#include <string.h>

int numE;
int i;

int addEmployee(void)
{
    struct employeelist employee[5]; 
    int numE; 


    printf("How many employees do you want to add to the list?: ");
    scanf("%d", &numE);
    printf("Please type in the last name, the first name,\nthe personal number and the salary of your employees.\n");

    for (i=0; i < numE; i++)
    {

    printf("Last name: ");
    scanf("%s", employee[i].last);  

    printf("First name: ");
    scanf("%s", employee[i].first);  

    printf("Personal number: ");
    scanf("%d", &employee[i].pnumber);  

    printf("Salary: ");
    scanf("%d", &employee[i].salary);  
    }

    return numE;
}

int printEmployee(int emp)
{
    struct employeelist employee[5]; 
    for (i=0; i < emp; i++)
    {

        printf("Last name: {%s}\nFirst name: {%s}\nPersonal number: {%d}\nSalary: {%d}\n",employee[i].last,employee[i].first, employee[i].pnumber, employee[i].salary);
    }

    getchar();
    getchar();
    return emp;
}

The last file contains the main() function to execute the functions above.

#include "employee.h"
#include <stdio.h>
#include <ctype.h>
#include <string.h>

int emp;

int main ()
{
    struct employeelist employee[5]; 
    int emp = addEmployee();
    printEmployee(emp);
    return 0;
}

Now my problem is that everything works only the output is incorrect. I can’t even say what it is. Some kind of random mix of signs, letters and numbers. Since i have no idea where my mistake is, i would be glad about any advise to solve this problem. Thank you.

I have added a screenshot of my output. Maybe it helps.

Answer 1

You’re trying to use a local variable, which ceases to exist when the function returns.

int addEmployee(void)
{
    struct employeelist employee[5];
    /* ... */
}

The variable employee only exists inside the addEmployee() function; and it is a different object every time the function is called.

int printEmployee(int emp)
{
    struct employeelist employee[5];
    /* ... */
}

This employee has no relation to the one in addEmployee.

---

But don’t do the easy thing now (*); do the right thing: declare the array in the main() function and pass it around.

//employee.h

struct employeelist 
{
    char last [20];
    char first[20];
    int pnumber;
    int salary;
};

/* add up to `maxemp` employees to the array and
** return  number of employees added */
int addEmployee(struct employeelist *, int maxemp);

/* print all employees from index 0 to (nemp - 1) */
int printEmployee(struct employeelist *, int nemp);

Declare an array in main(), and pass it around

#include "employee.h"
#include <stdio.h>
#include <ctype.h>
#include <string.h>

int main ()
{
    int emp;

    struct employeelist employee[5]; 
    int emp = addEmployee(employee, 5);
    printEmployee(employee, emp);
    return 0;
}

_{(*) Don’t declare a global variable for employees}

---

Edited employee.h and added a main() function