What is the output of following program? CPP #include <iostream> using namespace std; class Point { int x, y; public: Point(const Point &p) { x = p.x; y = p.y; } int getX() { return x; } int getY() { return y; } }; int main() { Point p1; Point p2 = p1; cout << "x = " << p2.getX() << " y = " << p2.getY(); return 0; }

x = garbage value y = garbage value

Constructors & Destructor

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Question 1

When a copy constructor may be called?

A
When an object of the class is returned by value.
B
When an object of the class is passed (to a function) by value as an argument.
C
When an object is constructed based on another object of the same class
D
When compiler generates a temporary object.
E
All of the above

Question 2

What is the output of following program?

CPP

#include 
using namespace std;

class Point
{
    int x, y;
public:
   Point(const Point &p) { x = p.x; y = p.y; }
   int getX() { return x; }
   int getY() { return y; }
};

int main()
{
    Point p1;
    Point p2 = p1;
    cout << "x = " << p2.getX() << " y = " << p2.getY();
    return 0;
}

A
x = garbage value y = garbage value
B
x = 0 y = 0
C
Compiler Error

Question 3

Predict the output of the following program?

C++

#include 
using namespace std;

class GfG {
    GfG() {
        cout << "Constructor Called" << endl;
    }
};

int main() {
    cout << "Main Started" << endl;
    return 0;
}

A
Compiler Error
B
Main Started
Constructor Called
C
Constructor Called
Main Started
D
Main Started

Question 4

Predict the output of following C++ progran

CPP

#include 
using namespace std;
 
int i;
 
class A
{
public:
    ~A()
    {
        i=10;
    }
};
 
int foo()
{
    i=3;
    A ob;
    return i;
}
 
int main()
{
    cout << foo() << endl;
    return 0;
}

A
0
B
3
C
10
D
None of the above

Question 5

Like constructors, can there be more than one destructors in a class?

A
Yes
B
No

Question 6

CPP

#include 
using namespace std; 
class A
{
    int id;
    static int count;
public:
    A() {
        count++;
        id = count;
        cout << "constructor for id " << id << endl;
    }
    ~A() {
        cout << "destructor for id " << id << endl;
    }
};
 
int A::count = 0;
 
int main() {
    A a[3];
    return 0;
}

constructor for id 1
constructor for id 2
constructor for id 3
destructor for id 3
destructor for id 2
destructor for id 1

constructor for id 1
constructor for id 2
constructor for id 3
destructor for id 1
destructor for id 2
destructor for id 3

C
```
Compiler Dependent.
```

constructor for id 1
destructor for id 1

Question 7

Which of the following is true about this pointer?

A
It is passed as a hidden argument to all function calls
B
It is passed as a hidden argument to all non-static function calls
C
It is passed as a hidden argument to all static functions
D
None of the above

Question 8

What is the use of this pointer?

A
When local variable’s name is same as member’s name, we can access member using this pointer.
B
To return reference to the calling object
C
Can be used for chained function calls on an object
D
All of the above

Question 9

Predict the output of following C++ program

CPP

#include
using namespace std;

class Test
{
private:
  int x;
  int y;
public:
  Test(int x = 0, int y = 0) { this->x = x; this->y = y; }
  static void fun1() { cout << "Inside fun1()"; }
  static void fun2() { cout << "Inside fun2()"; this->fun1(); }
};

int main()
{
  Test obj;
  obj.fun2();
  return 0;
}

A
Inside fun2() Inside fun1()
B
Inside fun2()
C
Inside fun1() Inside fun2()
D
Compiler Error

Question 10

What is the purpose of a default constructor in C++?

A
To create an object with default values
B
To create an object with specific initial values
C
To create a copy of an existing object
D
To transfer resources from a temporary object

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C++

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