Question

About Classes and OOP in C++

Part 1

Task 1: Create a class called Person, which has private data members for name, age, gender, and height. You MUST use this pointer when any of the member functions are using the member variables.

• Implement a constructor that initializes the strings with an empty string, characters with a null character and the numbers with zero.

• Create getters and setters for each member variable. Ensure that you identify correctly which member functions should be constant functions.

• Create a main function. Create three instances of Person. Assign a name, age, gender and height to each person by using the setters. And print out to the screen the information for each person using the getters.

Task 2: Create a private member variable called totalPerson that is shared by all the objects of the class Person. This member variable keeps track of how many instances of class Person has been created, thus this member variable should increment every time a new instance of class Person is created. You should also implement a member function that returns the value of the totalPerson. You should be able to call this member function even without making any instance of the class Person.

At this time, you should also create a destructor for class Person. Since all member variables are primitive types, there is really nothing to destroy or delete in terms of dynamic memory. However, what should you write in the destructor?

In the main function, add another code that prints out the total number of instances of the Person class. Create another instance of the Person class, this time, it should be dynamically allocated. Assign a name, age, gender and height to this person. And print out the person’s information to the screen.

Print out again the total number of instances of the Person class.

Delete the dynamically created instance of Person.

Print out again the total number of instances of the Person class.

Part 2 - Check Writing

Design a class Numbers that can be used to translate whole dollar amounts in the range 0 through 9999 into an English description of the number. For example, the number 713 would be translated into the string seven hundred thirteen, and 8203 would be translated into eight thousand two hundred three.

The class should have a single integer member variable

int number;

and a collection of static string members that specify how to translate key dollar amounts into the desired format. For example, you might use static strings such as

string lessThan20[] = {“zero”, “one”, …, “eighteen”, “nineteen”};

string hundred = “hundred”;

string thousand = “thousand”;

The class should have a constructor that accepts a non-negative integer and uses it to initialize the Numbers object. It should have a member function print() that prints the English description of the Numbers object. Demonstrate the class by writing a main program that asks the user to enter a number in the proper range and then prints out its English description.

Task 3: Create another instance of the Person class. After declaration, assign the first person to this new instance by using the assignment operator (=). Print out to the screen the information of this new instance. Is the information the same as the first person information? If it is, why?

Answer 1

Part 1

Task 1:

#include <bits/stdc++.h>

using namespace std;

class Person{
private:
string name,gender;
int age,height; // assumption : height is in cm(centimeter)
  
public:
Person(){
name="";
gender="";
age=0;
height=0;
}
  
/* Function to Set Name of a Person */
void setName(string name){
this->name=name;
}
  
/* Function to Set Gender of a Person */
void setGender(string gender){
this->gender=gender;
}
  
/* Function to Set Age of a Person */
void setAge(int age){
this->age=age;
}
  
/* Function to Set Height of a Person */
void setHeight(int height){
this->height=height;
}
  
/* Function to Get Name of a Person */
string getName(){
return name;
}
  
/* Function to Get Gender of a Person */
string getGender(){
return gender;
}
  
/* Function to Get Height of a Person */
int getHeight(){
return height;
}
  
/* Function to Get Age of a Person */
int getAge(){
return age;
}
  
};
int main()
{
Person p[3]; // creating 3 instance of Person class
  
// initialising 3 instance of Person class
p[0].setName("Tanuj");
p[0].setHeight(162);
p[0].setAge(21);
p[0].setGender("Male");
  
p[1].setName("Sonam");
p[1].setHeight(150);
p[1].setAge(20);
p[1].setGender("Female");
  
p[2].setName("Ajay");
p[2].setHeight(155);
p[2].setAge(25);
p[2].setGender("Male");
  
  
//displaying person information
for(int i=0;i<3;i++){
cout<<"Name : "<<p[i].getName()<<"\nGender : "<<p[i].getGender()<<"\nAge : "<<p[i].getAge()<<"\nHeight : "<<p[i].getHeight()<<" cm"<<endl<<endl;
}
  
return 0;
}

Task 2:

#include <bits/stdc++.h>

using namespace std;

class Person{
private:
string name,gender;
int age,height; // assumption : height is in cm(centimeter)
static int totalPerson; // static data member is used so that it can be used be shared by all the object of class
  
public:
Person(){
name="";
gender="";
age=0;
height=0;
totalPerson++;
}
  
/* Function to Set Name of a Person */
void setName(string name){
this->name=name;
}
  
/* Function to Set Gender of a Person */
void setGender(string gender){
this->gender=gender;
}
  
/* Function to Set Age of a Person */
void setAge(int age){
this->age=age;
}
  
/* Function to Set Height of a Person */
void setHeight(int height){
this->height=height;
}
  
/* Function to Get Name of a Person */
string getName(){
return name;
}
  
/* Function to Get Gender of a Person */
string getGender(){
return gender;
}
  
/* Function to Get Height of a Person */
int getHeight(){
return height;
}
  
/* Function to Get Age of a Person */
int getAge(){
return age;
}
  
// Function to Get Total Number of Person */
static int getTotalPerson(){
return totalPerson;
}
  
// Destructor of Person
~Person(){
cout<<"\nDestructor is called";
}
};

// initialising totalPerson
int Person::totalPerson=0;

int main()
{
Person* p= new Person[3]; // creating 3 object of Person Class Dynamically
  
// initialising 3 instance of Person class
p[0].setName("Tanuj");
p[0].setHeight(162);
p[0].setAge(21);
p[0].setGender("Male");
  
p[1].setName("Sonam");
p[1].setHeight(150);
p[1].setAge(20);
p[1].setGender("Female");
  
p[2].setName("Ajay");
p[2].setHeight(155);
p[2].setAge(25);
p[2].setGender("Male");
  
  
//displaying person information
for(int i=0;i<3;i++){
cout<<"Name : "<<p[i].getName()<<"\nGender : "<<p[i].getGender()<<"\nAge : "<<p[i].getAge()<<"\nHeight : "<<p[i].getHeight()<<" cm"<<endl<<endl;
}
  
// displaying total person
int totalPerson = Person::getTotalPerson();
cout<<"Total Person = "<<totalPerson<<endl;
  
  
// destroying an object of Person class
delete[] p;
  
return 0;
}