Operators and ennumerated types CPPE2 M4 Test

Operators and ennumerated types CPPE2 M4 Test

Operators and enumerated types CPPE2 M4 Test

  1. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class N {
public:
    float x;
    N() { x = 0.0; }
    N(float a) {x = a; }
    N(N &n) { x = n.x; }
    N &operator<<(N &y) { return *new N(x * 10); }
};

int main()
{
    N a(2.0),b(4.0);
    N c = a << 1;
    cout << c.x;
    return 0;
}
    • 0
    • Compilation fails
    • 2
    • 1

  2. What is the output of the following snippet?

    #include <iostream>
#include <string>
using namespace std;

class N {
public:
    float x;
    N() { x = 0.0; }
    N(float a) {x = a; }
    N(N &n) { x = n.x; }
    string operator==(N &n) { if(this != &n) return "true"; else return "false"; }
};

int main()
{
    N a(1.1), *b = &a;
    cout << (a == *b);
    return 0;
}
    • Compilation fails
    • It prints an empty string
    • false
    • true

  3. What is the output of the following snippet?

    #include <iostream>
using namespace std;
class Int {
public:
    int v;
    Int(int a) { v = a; }
    Int &operator--() {
       ++v;
       return *this;
    }
    Int &operator--(int v) {
       v+=2;
       return *this;
    }
};

ostream &operator <<(ostream &o, Int &a) {
       return o << a.v++;
}
int main()
{
    Int i = 0;
    cout << --i << i--;
    return 0;
}
    • 12
    • 21
    • 10
    • 23

  4. What is the output of the following snippet?

    #include <iostream>
using namespace std;
class Int {
public:
    int v;
    Int(int a) { v = a; }
};

int main()
{
    Int i = 1;
    cout << i;
    return 0;
}
    • 2
    • 0
    • 1
    • Compilation fails

  5. What is the output of the following snippet?

    #include <iostream>
using namespace std;

enum T { A =2, B = -1, C };

T operator+(T t, int i) {
    switch(t) {
        case A: return T(0);
        case B: return static_cast<T>(2);
    default:return (T)1;
    }
}

int main()
{
    T i = A + 2;
    cout << i;
    return 0;
}
    • 1
    • 0
    • Compilation fails
    • 2

  6. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class Int {
public:
    int v;
    Int(int a) { v = a; }
};

ostream &operator <<(ostream &o, Int &a) {
    return o << --a.v;
}

int main()
{
    Int i = 1;
    cout << i;
    return 0;
}
    • Compilation fails
    • 2
    • 1
    • 0

  7. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class N {
public:
    float x;
    N() { x = 0.0; }
    N(float a) {x = a; }
    N(N &n) { x = n.x; }
    N &operator%(N &y) { return *new N((int)x % (int)y.x); }
};

int main()
{
    N a(2.0),b(4.0);
    N c = a % b;
    cout << c.x;
    return 0;
}
    • Compilation fails
    • 1
    • 2
    • 0

  8. What is the output of the following snippet?

    #include <iostream>
using namespace std;

string operator>(float l, float r) { 
   if(int(l) > int(r)) 
     return "true";
   else return "false"; 
}
int main()
{
    float l =2.0, r =2.9999;
    cout << (l > r);
    return 0;
}
    • false
    • It prints an empty string
    • true
    • Compilation fails

  9. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class Int {
public:
    int v;
    Int(int a) { v = a; }
    Int &operator--() {
       ++v;
       return *this;
    }
};

ostream &operator <<(ostream &o, Int &a) {
    return o << --a.v;
}
int main()
{
    Int i = 2;
    cout << i;
    return 0;
}
    • 0
    • 1
    • Compilation fails
    • 2

  10. What is the output of the following snippet?

    #include <iostream>
using namespace std;
class Int {
public:
    int v;
    Int(int a) { v = a; }
    Int &operator[](int x) {
       v+=x;
    }
};

ostream &operator <<(ostream &o, Int &a) {
    return o << a.v;
}

int main()
{
    Int i = 2;
    cout << i.v << i[2];
    return 0;
}
    • Compilation fails
    • 33
    • 24
    • 44

  11. What is the output of the following snippet?

    #include <iostream>
using namespace std;

enum T { A, B, C };

class Int {
public:
    T v;
    Int(T a) { v = a; }
};

ostream &operator <<(ostream &o, Int &a) {
    return o << a.v;
}
int main()
{
    Int i = B;
    cout << i;
    return 0;
}
    • 1
    • 0
    • Compilation fails
    • B

  12. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class N {
public:
    string n;
    X(string s) : n(s) {}
    void operator() (X x) {
       cout << x.n;
    }
};

int main()
{
      X x("a", y("b");
      x(y);
    y(x);
    return 0;
}
    • ba
    • ab
    • Compilation fails
    • It prints an empty string

  13. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class N {
public:
    float x;
    N() { x = 0.0; }
    N(float a) {x = a; }
    N(N &n) { x = n.x; }
};

N &operator=(N &y,float f) { return *new N(f); }

int main()
{
    N a;
    a = 2.0;
    cout << a.x;
    return 0;
}
    • 2
    • 0
    • 1
    • Compilation fails

  14. What is the output of the following snippet?

    #include <iostream>
using namespace std;

enum T { A = 2, B = -1, C };

class Int {
public:
    T v;
    Int(T a) {  v = a; }
    Int & operator++() { v = C; return &this; }
};

ostream &operator <<(ostream &o, Int &a) { 
    ++a;
return o << a.v;
}

int main()
{
    Int i = B;
    cout << i;
    return 0;
}
    • 1
    • Compilation fails
    • C
    • 0

  15. What is the output of the following snippet?

    #include <iostream>
using namespace std;
class Int {
public:
    int v;
    Int(int a) { v = a; }
    Int &operator--() {
       ++v;
       ++v;
       return *this;
    }
};

ostream &operator <<(ostream &o, Int &a) {
    return o << a.v++;
}

int main()
{
    Int i = 0;
    cout << --i;
    return 0;
}
    • 0
    • 2
    • Compilation fails
    • 1

  16. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class Int {
public:
    int v;
    Int(int a) { v = a; }
    Int &operator++(int x) {
       v+=2;
       return *this;
    }
};

ostream &operator <<(ostream &o, Int &a) {
    return o << a.v;
}

int main()
{
    Int i = 0;
    cout << i++ << i.v;
    return 0;
}
    • 22
    • Compilation fails
    • 21
    • 20

  17. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class N {
public:
    float x;
    N() { x = 0.0; }
    N(float a) {x = a; }
    N(N &n) { x = n.x; }
    N &operator=(float f) { x = f - 1; return *this; }
};

int main()
{
    N a;
    a = 2.0;
    cout << a.x;
    return 0;
}
    • Compilation fails
    • 2
    • 1
    • 0

  18. What is the output of the following snippet?

    #include <iostream>
using namespace std;
class Int {
public:
    int v;
    Int(int a) { v = a }
};

ostream &operator <<(Int &a) {
    return cout << a.v;
}

int main()
{
    Int i = 1;
    cout << i;
    return 0;
}
    • 0
    • 2
    • Compilation fails
    • 1

  19. What is the output of the following snippet?

    #include <iostream>
using namespace std;

enum T { A = 2, B = -1, C };

class Int {
public:
    T v;
    Int(T a) { v = a; }
    Int & operator++() { v += 2; return *this; }
};

ostream &operator <<(ostream &o, Int &a) {
    ++a;
    return o << a.v;
}

int main()
{
   Int i = B;
    cout << i;
    return 0;
}
    • 0
    • 2
    • Compilation fails
    • 1

  20. What is the output of the following snippet?

    #include <iostream>
#include <string>
using namespace std;

class N {
public:
    float x;
    N() { x = 0.0; }
    N(float a) {x = a; }
    N(N &n) { x = n.x; }
    string operator==(float f) { 
        if(int(x) == int(f)) 
           return "true"; 
        else return "false"; 
    }
};

int main()
{
    N a(1.1);
    cout << ( a == 1.9);
    return 0;
}
    • Compilation fails
    • It prints an empty string
    • true
    • false