Question

C++

This exercise will introduce static member variables and static methods in class to you.

Class Department contain information about universities departments:

• name
• students amount

in addition it also stores information about overall amount of departments at the university:

• departments amount

class Department {
public:
    Department(string i_name, int i_num_students);
    ~Department();
    int get_students();    
    string get_name();   
    static int get_total();
private:
    string name;
    int num_students;
    static int total_departments;
};

Carefully read and modify the template.

You have to implement private static variable "total departments" which should contain the counter for the total number of initialised departments objects. In addition implement static public method get_total() Keep in mind that any modifications of this variable should be processed directly inside constructor/destructor.

#include
#include
using namespace std;

class Department {
public:
  
// Constructor definition
Department(string i_name, int i_num_students) {
cout << "Constructor called for: " << i_name << endl;
... // Assigne name and number of students
... // Increase every time object is created
}
  
// Destructor definition
~Department() {
cout << "Destructor called for: " << name << endl;
... // Decrease every time object is created
}
  
  
int get_students() {
...
}
  
string get_name() {
...
}
  
// Static function to return departments count
static int get_total() {
...
}
  
  
private:
string name;
int num_students;
  
// Static private variable 'total_departments'
...
};

// Initialize static member of class Department
int Department::total_departments = 0;

int main(void) {
  
// Create two departments
Department dep1("CS", 2000);
Department dep2("BIO", 3000);
  
  
// Call destructor for dep1
dep1.~Department();
  
// Print total number of objects
cout << "Total departments: " << Department::get_total() << endl;
cout << "Here is the end of the main." << endl;
return 0;
}

Answer 1

#include <iostream>

using namespace std;

class Department {

public:

// Constructor definition

Department(string i_name, int i_num_students) {

cout << "Constructor called for: " << i_name << endl;

// Assigne name and number of students

name = i_name;

// Increase every time object is created

num_students = i_num_students;

++total_departments;

}

// Destructor definition

~Department() {

cout << "Destructor called for: " << name << endl;

--total_departments;

}

int get_students() {

return num_students;

}

string get_name() {

return name;

}

// Static function to return departments count

static int get_total() {

return total_departments;

}

private:

string name;

int num_students;

// Static private variable 'total_departments'

static int total_departments;

};

// Initialize static member of class Department

int Department::total_departments = 0;

int main(void) {

// Create two departments

Department dep1("CS", 2000);

Department dep2("BIO", 3000);

// Call destructor for dep1

dep1.~Department();

// Print total number of objects

cout << "Total departments: " << Department::get_total() << endl;

cout << "Here is the end of the main." << endl;

return 0;

}

=============================================
SEE OUTPUT

Thanks, PLEASE COMMENT if there is any concern.