COMPUTER SCIENCE CONSTRUCTORS AND DESTRUCTORS

DELHI 2006:

2.b) Answer the following questions (i) and (ii) after going through the following class.

class Interview { int Month;
public:
interview(int y) {Month=y;}
//constructor 1
interview(Interview&t);
//constructor 2
};

2

(i) create an object, such that it invokes Constructor .

1

Ans: Interview A(10); //invoking constructor 1 by passing a number.

(ii) write complete definition for Constructer .

2

Ans: Interview(Interview &t) //This is a copy constructor.

{ Month=t.Month;
}

OUTSIDE DELHI 2006:

1.f) What is a default constructor? How does it differ from destructor?

2

a) Default constructor: A constructor that accepts no parameter is called the default constructor. With a default constructor, objects are created just the same way as variables of other data types are created.

class X
{ int i ;
public:
int j, k ;
------ //Members
Functions
------
};

Eg: X ob1;
Student s1;

If a class has no explicit constructor defined, the compiler will supply a default constructor. This implicitly declared default constructor is an inline public members of its class. Declaring a constructor with arguments hides the default constructor.There can be a default constructor as well as another constructor with arguments for a class, having multiple constructors is called as constructor overloading.

2.b) Answer the following questions (i) and (ii)after going through the following class.

class Exam
{ int Year;
public:
Exam(int y) //Constructor 1
{ Year=y;
}
Exam(Exam &t);
//Constructor 2
};

2

(i) Create an object, such that it invokes Constructor .

1

Ans: Exam E((2008);

(ii) Write complete definition for constructor .

2

Ans: Exam(Exam &t) //Copy Constructor.

{ Year=t.Year;
}

 

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