Answer 1

union are collection of different datatype. They are used to group number of variables of different type in a single unit.

for example

#include<iostream.h>

union Employee
{
int Id;
char Name[25];
int Age;
long Salary;
};

void main()
{

Employee E;

cout << "\nEnter Employee Id : ";
cin >> E.Id;
cout << "Employee Id : " << E.Id;

cout << "\n\nEnter Employee Name : ";
cin >> E.Name;
cout << "Employee Name : " << E.Name;

cout << "\n\nEnter Employee Age : ";
cin >> E.Age;
cout << "Employee Age : " << E.Age;

cout << "\n\nEnter Employee Salary : ";
cin >> E.Salary;
cout << "Employee Salary : " << E.Salary;

}

Output :

Enter Employee Id : 1
Employee Id : 1

Enter Employee Name : Kumar
Employee Name : Kumar

Enter Employee Age : 29
Employee Age : 29

Enter Employee Salary : 45000
Employee Salary : 45000