C++ Essentials CPPE2: Part 2 Summary Test

C++ Essentials CPPE2: Part 2 Summary Test

C++ Essentials CPPE2: Part 2 Summary Test

  1. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class C1 {
friend class C2;
protected: int y;
public:    int z;
private:   int x;
public:    C1() { x = y = z =11; }
};

class C2 {
public: C1 a;
        C2 () { a.x = 22; };
        void foo() {
           cout << a.x << a.y << a.z;
        }
};
int main()
{
   C2 c;
   c.foo();
   return 0;
}
    • 111122
    • Compilation fails
    • 221111
    • 112211

  2. What is the output of the following snippet?

    #include <iostream>
using namespace std;

class SupClass {
public:
       void show(int par){ cout << par + 1;}
};

class SubClass : public SupClass {
public: 
       void show(float par) { cout << par + 2;}
};
int main()
{
   SubClass o;
   o.show(2.0);
}
    • 2
    • 1
    • 4
    • 3

  3. What is the output of the following snippet?

    #include <iostream>
void fun(int *i) 
{
   *i = *i >> *i - 1;
}
using namespace std;
int main()
{
   int i = 2;
   fun(&i);
   cout << i;
   return 0;
}
    • 4
    • 2
    • 1
    • 0

  4. Which code, inserted into funtion main ,generates the output abba ? Choose all correct answers.

    #include <iostream>
#include <string>
using namespace std;
string fun(string s)
{
    return s.substr(0,1)+s.substr(1,1)+s.substr(1,1)+s.substr(0,1);
}
int main()
{
    string *s = new string("ab");
    //insert code here
    return 0;
}
    • cout << fun(*s);
    • cout << fun("abba");
    • cout << fun("ab");
    • cout << fun(s);

  5. What is the output of the following snippet?

    #include <iostream>
using namespace std;
class Zero
{ public: void out(){ cout << 0;} };
class One: public Zero
{ public: void out(){ cout << 1;} };
class Two : public Zero
{ public: void out(){ cout << 2;} };
int main()
{
   Zero *obj;
   One obj1;
   obj = &obj1;
   obj->out();
   Two obj2;
   obj = &obj2;
   obj->out();
   return 0;
}
    • 00
    • 12
    • 01
    • 02

  6. Which of the following statements are correct about the following array?

    char array[255];
    • The array may be initialized at the time of declaration.
    • The expression tab[225] designates the last element in the array.
    • The expression tab[2] designates the second element in the array.
    • The array can store 255 elements.

  7. What is the output of the following snippet?

    #include <iostream>
using namespace std;

void foo(int &parameter)
{
   parameter *= 2;
}
int main()
{
   int var = 2;
   foo(var);
   cout << var;
   return 0;
}
    • 1
    • 8
    • 2
    • 4

  8. What is the output of the following snippet?

    #include <iostream>
using namespace std;
class one {
public:
   void foo() { cout << 1; }
};
class two {
public:
    void foo() { cout << 2;}
};
int main()
{
   two objects[2];
   two *object = objects;
   for(int i = 0; i < 2; i++)
      (object++)->foo();
   return 0;
}
    • 11
    • 12
    • 22
    • 21

  9. Which code, inserted into the One class , generates the output 123?

    #include <iostream>
using namespace std;
class One {
public:
  //insert code here
};
class Two : public One {
public:
   void foo() { cout << 2; }
};
class Three : public Two{
public:
    void foo() {cout << 3;}
};
int main()
{
    One o1;
    Two o2;
    Three o3;
    One *o = &o1;
    o->foo();
    o = &o2; o->foo();
    o = &o3; o->foo();
}
    • static void foo(){ cout << 1; }
    • void foo(){ cout << 1; }
    • virtual void foo(){ cout << 1; }
    • None of these

  10. What is the output of the following snippet?

    #include <iostream>
using namespace std;
int main() {
   int i = 2;
   if(i--==1)
      cout << i;
   else
      cout << i + 1;
   return 0;
}
    • 1
    • 8
    • i + 1
    • 2

  11. What is the output of the following snippet?

    #include <iostream>
#include <sstream>
#include <string>
using namespace std;
int main()
{
    string s;
    s = "abcd";
    s.append(s);
    s.resize(s.size() / 2);
    cout << s;
    return 0;
}
    • abcdabcd
    • It prints an empty string
    • Compilation fails
    • abcd

  12. What is the output of the following snippet?

    #include <iostream>
using namespace std;
int main()
{
    int a = -1, *p = &a;
    cout << ((p == NULL) ? 1.1 : 2.2);
    return 0;
}
    • 1.1
    • Compilation error
    • None of these
    • 2.2

  13. Variable c in class B, will be:

    class A {
    int a;
protected:
    int b;
public:
    int c;
};

class B : public A {
    float f;
public:
    void foo() {
        cout << f << c;
    }
};
    • protected
    • public
    • none of these
    • private

  14. What is the output of the following snippet?

    #include <iostream>
#include <string>
using namespace std;
int main()
{
   string s1 = "foo";
   string s2;
   getline(cin,s2);
   cout << s2.append(s1);
   return(0);
}
    • foo
    • barfoo
    • bar
    • foobar

  15. What is the output of the following snippet?

    #include <iostream>
using namespace std;
int var = -1;
int static Static(int i)
{
    static int y = 0;
    y += ++i;
    return y;
   }
   int main()
   {
       var++;
       Static(var++);
       cout << var << Static(var);
}
    • 13
    • 9
    • 7
    • 11

  16. Which code, inserted into the B class, generates the output ef ?

    #include <iostream>
#include <string>
using namespace std;
class Alpha{
      int p;
protected:
      int q;
public:
      int r;
      Alpha():p(2), q(3),r(4){}
};
class Beta: public Alpha{
      string s;
public:
      int y;
      void assign() {y = 4; s = "f";}
      void out(){
          //insert code here
      }
};
int main(){
      Beta b;
      b.assign();
      b.out();
      return 0;
}
    • cout << char('a' + r) << s;
    • cout << p << r;
    • cout << r << s;
    • cout << 'a' + r << s;

  17. How can we pass argument to functions?

    • None of these 
    • By default 
    • By invocation
    • By telepathy

  18. What is the output of the following snippet?

    #include <iostream>
#include <string>
using namespace std;
int f(int a)
{
   return a + a;
}
int main()
{
   int i = 0;
   for(int a = 0; a < 2; a++)
       i = f(i + 1);
   cout << i;
   return 0;
}
    • 9
    • 6
    • 2
    • 3

  19. What is the output of the following snippet?

    #include <iostream>
using namespace std;
int sub(int x, int y)
{
    x -= y;
    return x;
}
int main()
{
    int a = 0, b = 1, c,d;
    c = sub(a,b);
    d = sub(c,d);
    cout << c << d;
    return 0;
}
    • 1-2
    • -12
    • -1-2
    • 12

  20. What is the output of the following snippet?

    #include <iostream>
using namespace std;
int main(int argc, const char * argv[])
{
   double dbl = -5.55;
   cout << (int)dbl;
}
    • -6
    • -5.5
    • 0
    • -5

  21.  What is the output of the following snippet?

    #include <iostream>
using namespace std;
char fun(char *p)
{
   char c = *p;
   (*p)++;
   return c;
}
int main()
{
   char array[3] = {'a', 'b', 'c'};
   fun(array + 1);
   cout << fun(array + 1);
   return 0;
}
    • b
    • a
    • Compilation fails
    • c

  22.  What is the output of the following snippet?

    #include <cstdlib>
#include <iostream>
using namespace std;
char c;
char *inc(char par1, int par2)
{
    c = par1 + par2;
    return &c;
}
int main()
{
    int a = 'a', b = 3;
    char *f;
    f = inc(a,b);
    cout << *f;
    return 0;
}
    • d
    • c
    • c
    • a

  23.  What is the output of the following snippet?

    #include <iostream>
using namespace std;

int main()
{
   int va1 = 0, *adr = &va1;
   cout << *va1;
   return 0;
}
    • 0
    • 1
    • Compilation fails
    • It prints address of val

  24. Which code, inserted into the main function, generates the output za

    #include <iostream>
using namespace std;
namespace SpaceOne{char a = 'a';}
namespace SpaceTwo{char a ='z';}
int main(){
    // insert code here
    return 0;
}
    • cout << SpaceTwo::a << SpaceOne::a;
    • cout << a << a;
    • cout << SpaceOne::a <<SpaceTwo::a;
    • None of these

  25. Which code, inserted into the main function, generates the output a 2

    #include <iostream>
using namespace std;
namespace Space 
{ char a = 'a', b = 'b';}
int a = 1, b = 2;

int main(){
    // insert code here
    cout << a << " " << b;
    return 0;
}
    • None of these 
    • using Space::a;
    • using namespace Space::a;
    • using namespace Space;

  26.  What is the output of the following snippet?

    #include <iostream>
#include <string>
#include <exception>
using namespace std;
class a
{
public: virtual string whose()
       {return "mine";}
};
class b
{
public: virtual string whose()
       {return "yours";}
};
int main(){
    a b;
    try{throw b;}
    catch(a& e){cout << e.whose() <<endl;}
    return 0;
}
    • yours
    • mineyours
    • yoursmine
    • mine

  27.  What is the output of the following snippet?

    #include <iostream>
#include <string>

using namespace std;

int main()
{
   string s1[] = {"A", "Z"};
   string s ="";
   for(int i =0; i < 2; i++)
       cout << s.append(s1[i]).insert(1,"_");
   return (0);
}
    • A_A
    • A__Z
    • A_A_Z
    • A_A__Z

  28.  What is the output of the following snippet?

    #include <iostream>
using namespace std;

int main()
{
   char i = '1';
   switch(i)
   {
     case'1':
        cout << "Hello";
     case '2':
        cout << "world"; break;
     case '3':
        cout << "!";
        return 0;
    }
}
    • It prints nothing 
    • Hello world
    • Hello
    • Hello world !

  29.  What is the output of the following snippet?

    #include <iostream>
using namespace std;
class foo{
     int p;
protected:
     int q;
public:
     int r;
};

class bar: public foo{
public:
     void assign(){
         p = q = r = 2;
     }
     void out() {cout << q << r;}
};

int main(){
     bar b;
     b.assign();
     b.out();
     return 0;
}
    • Compilation fails
    • 20
    • 02
    • 22

  30. Which code, inserted into the Class , generates the output abcd ? 

    #include <iostream>
using namespace std;
class Class{
public:
   static char value;
   Class(){value++;};
   ~Class(){value++;};
   //insert code here
   void print(){cout << value;}
};
char Class::value = 'a';
 int main(){
    Class a,*b;
    b = new Class();
    b->set('a');
    b->print();
    delete b;
    a.print();
    a.set('c');
    a.print();
    a.set();
    a.print();
    return 0;
}
    • void set(char c = 'd'){value = c;}
    • void set() {value = 'd';}
    • void set (char c){cout << c;}
    • void set (char c) {value = c;}