In C++, we can pass a structure variable to a function as argument like we pass any other variable to a function. Structure variable is passed using call by value. To take a structure variable as argument, function must declare a structure argument in it's declaration. Any change in the value of formal parameter inside function body, will not affect the value of actual parameter.
For Example :
struct employee {
char name[100];
int age;
float salary;
char department[50];
};
void printEmployeeDetails(struct employee emp);
We can also pass address of a structure to a function. In this case, any change in the formal parameter inside function's body will reflect in actual parameter also. To take a structure pointer as parameter a function declare a a structure pointer as it's formal parameter.
void printEmployeeDetails(struct employee *emp);Like any other inbuilt data type, we can also pass individual member of a structure as function argument.
C++ Program to Pass Structure Variable to a Function
#include <iostream>
using namespace std;
struct employee {
char name[100];
int age;
float salary;
char department[50];
};
// This function takes structure variable as parameter
void printEmployeeDetails(struct employee emp){
cout << "\n*** Employee Details ***\n";
cout << "Name : " << emp.name << "\nAge : "<< emp.age << "\nSalary : "
<< emp.salary << "\nDepartment : "<< emp.department;
}
// This function takes structure pointer as parameter
void printEmployeeDetails(struct employee *emp){
cout << "\n--- Employee Details ---\n";
cout << "Name : " << emp->name << "\nAge : "<< emp->age << "\nSalary : "
<< emp->salary << "\nDepartment : "<< emp->department;
}
void printAge(int age){
cout << "\n\nAge = " << age;
}
int main(){
struct employee manager, *ptr;
printf("Enter Name, Age, Salary and Department of Employee\n");
// Assigning data to members of structure variable
cin >> manager.name >> manager.age >> manager.salary >> manager.department;
// Passing structure variable to function
printEmployeeDetails(manager);
// Passing address of structure variable to a function
printEmployeeDetails(&manager);
/* Passing structure member to function */
printAge(manager.age);
return 0;
}
Output
Enter Name, Age, Salary and Department of Employee David 32 98765 SDE *** Employee Details *** Name : David Age : 32 Salary : 98765 Department : SDE --- Employee Details --- Name : David Age : 32 Salary : 98765 Department : SDE Age = 32