1) Which of the following operators can use friend functions for overloading?
a) ==
b) [ ]
c) –>
d) ( )
Answer(s) : a) ==
[quads id=1]
2) What will be the O/P of the following program ?
#include
using namespace std;
class GlobalClass {
int m_value;
static GlobalClass *s_instance;
GlobalClass(int v = 0) {
m_value = v;
}
public:
int get_value() {
return m_value;
}
void set_value(int v) {
m_value = v;
}
static GlobalClass *instance() {
if (!s_instance)
s_instance = new GlobalClass;
return s_instance;
}
};
GlobalClass *GlobalClass::s_instance = 0;
void Func1(void) {
GlobalClass::instance()->set_value(1);
cout << GlobalClass::instance()->get_value() << ‘\n’; } void Func2(void){ GlobalClass::instance()->set_value(2);
cout << GlobalClass::instance()->get_value() << ‘\n’;
}
int main() {
cout << GlobalClass::instance()->get_value() << ‘\n’;
Func1();
Func2();
}
a)
0 1 1
b)
0 0 0
c)
0 1 2
d)
1 2 3
Answer(s) : c) 0 1 2
3) What is the output/Error of the following code ?
#include
using namespace std;
struct emp {
int a;
emp ( int b): a(b){cout << ” Constructor ” ;}
~emp(){ cout << ” Destructor ” ;}
void disp(){ cout << ” In Display ” ; }
};
int main(){
emp *e = new emp(20);
cout << e->a ;
e->disp();
}
a) a and disp cannot be accessed in main as it is private
b) a cannot be accessed in main as it is private
c) Constructor 20 In Display
d) Constructor 20 In Display Destructor
Answer(s) : c) Constructor 20 In Display
[quads id=1]
4) What is the output of the following code?
#include
using namespace std ;
namespace Ex { int x = 10; }
namespace Ex { int y = 10; }
int x = 5;
int main(){
using namespace Ex ;
x = y = 50;
cout << x << ” ” << y;
}
a) 10 10
b) 50 50
c) 5 50
d)
Compilation error: ambiguous reference to variable 'x'
Answer(s) : d) Compilation error: ambiguous reference to variable 'x'
5) Fill in the blank in the following program.
#include
using namespace std;
class Test { static int x;
public:
void get() { x = 15; }
void print() {
x = x + 20;
cout << “x =” << x << endl;
}
};
____________; // Define static variable ‘x’
int main() {
Test o1, o2;
o1.get(); o2.get();
o1.print(); o2.print();
return 0;
}
a)
int Test t.x = 0;
b)
Test t; t.x = 0;
c)
int Test::x = 0;
d)
t; t::x = 0;
Answer(s) : c) int Test::x = 0;
[quads id=1]
6) What will be the output of the following program ?
#include
using namespace std;
class Test { int x;
public:
Test(int i) : x(i) {}
friend void print(const Test& a);
};
void print(const Test& a) {
cout << “x = ” << a.x;
}
int main(){
Test t(10);
print(t);
return 0;
}
a)
x = 10
b)
Compilation Error: print cannot access x as it is private
c)
Compilation Error: illegal parameter passing in print
d)
Compilation Error: Const parameter cannot be passed in friend function
Answer(s) : a) x = 10
7) What will be the output of the following program ?
#include
using namespace std;
class sample {
public:
int x, y;
sample() {};
sample(int, int);
sample operator + (sample);
};
sample::sample (int a, int b) {
x = a;
y = b;
}
sample sample::operator+ (sample param) {
sample temp;
temp.x = x + param.x;
temp.y = y + param.y;
return (temp);
}
int main () {
sample a (4,1);
sample b (3,2);
sample c;
c = a + b;
cout << c.x << ” ” << c.y;
return 0;
}
a) 5 5
b) 7 3
c) 3 7
d) 4 6
Answer(s) : b) 7 3
[quads id=1]
8) What will be the output of the following program ?
#include
using namespace std;
class Test {
int i;
public:
Test(int ii) : i(ii) {}
const Test operator*(const Test& rv) const {
cout << “Executes *” << endl;
return Test(i * rv.i);
}
Test& operator+=(const Test& rv) {
cout << “Executes +=” << endl;
i += rv.i;
return *this;
}
};
int main() {
int i = 1, j = 2, k = 3;
k += i * j;
Test ii(1), jj(2), kk(3);
kk += ii * jj;
}
a)
b)
c)
d) Compilation Error: Ambiguous declaration
Answer(s) : a) Executes *Executes +=
