C++ Pointers to Structure

In this tutorial we are going to learn about how to use pointers to access data from structure.

A pointer can have data type other than predefined data types (i.e int, float, char or double etc.). Pointers can have user defined data types also like Structure.

Let us take an example:

#include <iostream>

using namespace std;

struct Student {

 int roll;
 char grade;
 float per;
};

int main() {

 Student S;
 Student *p;
 p=&S;
 return 0;
}

This program creates a pointer p of type structure student which is pointing to the memory address of variable s of type structure student.

---

Example 1 : Pointer to Structure

#include <iostream>

using namespace std;

struct Student
{

     int roll;
     char grade;
     float per;
};

int main()
{

     Student S;
     Student *p;

     p = &S;

     cout > (*p).roll;
     cout > (*p).grade;
     cout > (*p).per;
     cout 
            
There are two ways for accessing the members of the structure through
pointer:
            

                
(*p).data_member;
                
p->data_member;
            
            
The second way (i.e. p->data_member) is the most easy and widely
used way with structure as well as class. So the above example can
also be written as:
            
#include <iostream>
using namespace std;

struct Student
{
     int roll;
     char grade;
     float per;
};

int main()
{
     Student S;
     Student *p;

     p = &S;

     cout > p->roll;
     cout > p->grade;
     cout > p->per;

     cout roll grade per;

     return 0;
}

            
            
Output :
            
Enter roll: 10
Enter grade: A
Enter percentage: 90
Displaying information.
roll: 10
grade: A
percentage: 90
            
            
In this program, a pointer variable p and normal variable s of type
structure Student is defined.
            
The address of variable s is stored to pointer variable, that is, p is pointing
to the memory address of variable s. Then, the member function of
variable s is accessed using pointer.
            
Note: Since pointer p is pointing to the memory address of variable s in this
program, p->roll and s.roll is exact same cell.
Similarly,

p->grade and s.grade is exact same cell.

p->per and s.per is exact same cell.