Arrays In Structures

Structures can contain arrays and pointers. Given a structure representing a pupil: 
struct Pupil
{
    char name[20];
    int gradesArray[10]; // array of grades in ten different subjects
    Pupil *pStudyingMate; // points to the studying mate of this pupil
};
The structure contains the pupil's name and the pupil's grades. It is assumed that every pupil has a studying mate, whose corresponding structure is pointed to by pStudyingMate. Given a Pupil structure: 
Pupil pupil1;
its elements can be accessed through the dot . operator: 
strcpy(pupil1.name, "Jake");
this also holds for array elements: 
pupil1.gradesArray[0] = 5;
Pointers within structures can contain the address of any type of variable, including structures of the same type as the one containing the pointer: 
Pupil pupil2;
pupil2.pStudyingMate = &pupil1;
The statement above assigns the address of pupil1 to the pStudyingMate pointer within pupil2.

Example


#include <iostream>
#include <cstring>
using namespace std;

struct Pupil
{
    char name[20];
    int gradesArray[10];
    Pupil *pStudyingMate;
};

// prints structure's contents
void printPupil(Pupil aPupil) 
{
     cout << "name: " << aPupil.name << endl;
     cout << "grades: ";
     for (unsigned int i = 0; i <= 9; i++)
           cout << aPupil.gradesArray[i] << " ";
     cout << endl;
     if(aPupil.pStudyingMate != NULL)
           cout << "Studying mate: " << (aPupil.pStudyingMate)->name << endl;;
     cout << endl;
}

// initialize to 0 array of grades
void initializaGradesArray(Pupil &p) 
{
     for (unsigned int i = 0; i <= 9; i++)
           p.gradesArray[i] = 0;
}

int main()
{
    Pupil pupil1, pupil2; // structures' declaration

    // structures initialization
    strcpy(pupil1.name, "Jake");

    initializaGradesArray(pupil1);

    strcpy(pupil2.name, "Mary");
    initializaGradesArray(pupil2);

    pupil1.pStudyingMate = &pupil2; // Mary is Jake's studying mate

    pupil2.pStudyingMate = &pupil1; // Jake is Mary's studying mate

    printPupil(pupil1);
    printPupil(pupil2);
}

Output

name: Jake
grades: 0 0 0 0 0 0 0 0 0 0
Studying mate: Mary

name: Mary
grades: 0 0 0 0 0 0 0 0 0 0
Studying mate: Jake