Assignments » Constructor  »  set1

Constructor

[Set – 1]

1. Answer the questions (i) and (iii) after going through the following class:

class Seminar
{
    int time;
public:
    Seminar()        //Function 1
    {
        time = 30;
        cout << "Seminar starts now" << endl;
    }
    void lecture()        //Function 2
    {
        cout << "Lectures in the seminar on" << endl;
    }
    Seminar(int duration)        //Function 3
    {
        time = duration;
        cout << "Seminar starts now" << endl;
    }
    ~Seminar()        //Function 4
    {
        cout << "Thanks" << endl;
    }
};

i. Write statements in C++ that would execute Function 1 and Function 3 of class Seminar.

ii. In Object Oriented Programming, what is Function 4 referred as and when does it get invoked/called?

iii. In Object Oriented Programming, which concept is illustrated by Function 1 and Function 3 together?

Show the answer.

i.
Seminar s1;    // Execute funtion 1
Seminar s2(20);  //Execute function 3
ii.
Destructor, it is invoked as soon as the scope of the object
gets over.
iii.
Constructor Overloading (Polymorphism)

class Test
{
    char paper[20];
    int marks;
public:
    Test ()    // Function 1
    {
        strcpy (paper, "Computer");
        marks = 0;
    }
    Test (char p[])    // Function 2
    {
        strcpy(paper, p);
        marks = 0;
    }
    Test (int m)    // Function 3
    {
        strcpy(paper,"Computer");
        marks = m;
    }
    Test (char p[], int m)    // Function 4
    {
        strcpy (paper, p);
        marks = m;
    }
};

i. Write statements in C++ that would execute Function 1, Function 2, Function 3 and Function 4 of class Test.

ii. Which feature of Object Oriented Programming is demonstrated using Function 1, Function 2, Function 3 and Function 4 together in the above class Test?

Show the answer.

i.
Test t1;  // Execute funtion 1
Test t2("English"); // Execute funtion 2
Test t3(50); // Execute funtion 3
Test t4("Maths",49); // Execute funtion 4
ii.
Constructor Overloading (Polymorphism)

class Sample
{
private:
    int x;
    double y;
public :
    Sample(); //Constructor 1
    Sample(int); //Constructor 2
    Sample(int, int); //Constructor 3
    Sample(int, double); //Constructor 4
};

i. Write the definition of the constructor 1 so that the private member variables are initialized to 0.

ii. Write the definition of the constructor 2 so that the private member variable x is initialized according to the value of the parameter, and the private member variable y is initialized to 0.

iii. Write the definition of the constructors 3 and 4 so that the private
member variables are initialized according to the values of the parameters.

Show the answer.

i.
Sample :: Sample()
{
    x = 0;
    y = 0;
}
ii.
Sample :: Sample(int a)
{
    x = a;
    y = 0;
}
iii.
Sample :: Sample(int a, int b)
{
    x = a;
    y = b;
}
Sample :: Sample(int a, double b)
{
    x = a;
    y = b;
}