How to use a union along with two structs + more

Question

I'm having trouble with my assignment and was hoping to get some help.

I'm suppose to have two structs, volunteer and employee, and a union 'person' that takes firstname, lastname, telenumber + either volunteer or employee as a struct.

I have had experience using unions + structs before, but I'm suppose to have additional information in the union. I was wondering how I can set it up properly, this is what I have so far.

typedef struct volunteer{
    int hours;
    int tasksCompleted;
}student;

typedef struct employee{
    float salary;
    int serviceYears;
    int level;
}employee;

typedef union person{
    char firstName[20];
    char familyName[20];
    char telephoneNum[10];
    //employee e;
    //volunteer;
}person;

Any help would be great. This is the task instruction I'm stuck on.

Create a person record that consists of the common records: first name, family name and telephone and a union between the volunteer and employee record. Make sure that you add a field to discriminate between the two records types employee or volunteer.

Answer 1

I think you are overthinking this: you need a structure to represent person. The key part is

"and a union between the volunteer and employee record."

typedef enum { employee_person, volunteer_person }  person_type;
typedef struct person{
    char firstName[20];
    char familyName[20];
    char telephoneNum[10];
    person_type type;
    union {
        struct employee employee;
        struct volunteer volunteer;
    };
}person;

Answer 2

This should do what you ask:

typedef struct volunteer {
    int hours;
    int tasksCompleted;
} student;

typedef struct employee {
    float salary;
    int serviceYears;
    int level;
} employee;

struct person {
    char firstName[20];
    char familyName[20];
    char telephoneNum[10]; 
    bool is_employee;
    union {
        employee e;
        student s;
    } info;
} person;