Now youd need to create different variables for each

Now, you'd need to create different variables for each information per person: name1,
citNo1, salary1, name2, citNo2, salary2
You can easily visualize how big and messy the code would look. Also, since no relation
between the variables (information) would exist, it's going to be a daunting task.
A better approach will be to have a collection of all related information under a single
name Person, and use it for every person. Now, the code looks much cleaner, readable
and efficient as well.
This collection of all related information under a single name Person is a structure.
Declaration of a Structure in C++
Then inside the curly braces, you can declare one or more members (declare variables
inside curly braces) of that structure. For example:
struct Person
{
char name[50];
int age;
float salary;
};
Here a structure person is defined which has three members: name, age and salary.
When a structure is created, no memory is allocated. The structure definition is only the
blueprint for the creating of variables. You can imagine it as a datatype. When you define
an integer as below:
int foo;
The int specifies that, variable foo can hold integer element only. Similarly, structure
definition only specifies that, what property a structure variable holds when it is defined.
Defining Variable of a Structure
Once you declare a structure person as above. You can define a structure variable as:

Person bill;
Here, a structure variable bill is defined which is of type structure P erson.
When structure variable is defined, only then the required memory is allocated by the
compiler.
Considering you have either 32-bit or 64-bit system, the memory of float is 4 bytes,
memory of int is 4 bytes and memory of char is 1 byte.
Hence, 58 bytes of memory is allocated for structure variable bill.
Accessing members of a Structure
The members of structure variable is accessed using a dot (.) operator.
Suppose, you want to access age of structure variable bill and assign it 50 to it. You can
perform this task by using following code below:
bill.age = 50;
Example:
#include <iostream>
using namespace std;
struct Person
{
char name[ 50 ];
int age;
float salary;
};
int main()
{
Person p1;
cout << "Enter Full name: " ;
cin. get (p1.name, 50 );
cout << "Enter age: " ;
cin >> p1.age;
cout << "Enter salary: " ;
cin >> p1.salary;
cout << "\nDisplaying Information." << endl;
cout << "Name: " << p1.name << endl;
cout << "Age: " << p1.age << endl;
cout << "Salary: " << p1.salary;
return 0 ;
}

Output
Enter Full name: Magdalena Dankova
Enter age: 27
Enter salary: 1024.4
Displaying Information.
Name: Magdalena Dankova
Age: 27
Salary: 1024.4
Structure and Functions
Structure variables can be passed to a function and returned in a similar way as normal
arguments.
Example:
#include <iostream>
using namespace std;
struct Person
{
char name[ 50 ];
int age;
float salary;
};
void displayData( Person ); // Function declaration
int main()
{
Person p;
cout << "Enter Full name: " ;
cin. get (p.name, 50 );
cout << "Enter age: " ;
cin >> p.age;
cout << "Enter salary: " ;
cin >> p.salary;
// Function call with structure variable as an argument
displayData(p);
return 0 ;
}

void displayData( Person p)
{
cout << "\nDisplaying Information." << endl;
cout << "Name: " << p.name << endl;
cout << "Age: " << p.age << endl;
cout << "Salary: " << p.salary;
}
Output