C++ Essentials CPPE1: Part 1 Summary Test

C++ Essentials CPPE1: Part 1 Summary Test

1. What is the output of the following program if a digit 3 followed by Enter is entered through the keyboard?

   #include <iostream>
   using namespace std;
   int main()
   {
      int i = 2, j = i++, k = i++;
   
      cin >> i;
      cout << k - i << j - i;
   }

   • 0-2
   • -10
   • -1-2
   • 0-1

2. What is the final value of the k variable?

   #include <iostream>
   using namespace std;
   
   int main()
   {
      int i = 0, k = i;
      while(i==0){
          if(k > 1)
             i = k;
          ++k;
      }
      cout << k;
   }

   • 3
   • 1
   • 4
   • 2

3. What is the output of the following snippet?

   #include <iostream>
   using namespace std;
   
   float combine(float x1 = 0.0, int x2 = 1.0)
   {
      return x2 + x1;
   }
   int main()
   {
      cout << combine() + combine(1.) + combine(2.,3.);
   }

   • 8
   • 2
   • 4
   • 3

4. What is the output of the following snippet?

   #include <iostream>
   #include <vector>
   
   using namespace std;
   
   int main()
   {
      vector<float *> ft = {new float[1], new float[1], new float[1]};
      for(int i = 0; i < 3; i++) {
          float *p = ft[i];
          *p = i;
       }
       cout << *ft[1];
       for(int i = 0; i < 3; i++){
           delete[] ft[i];
       }
   }

   • 0
   • Compilation fails 
   • 1
   • 2

5. What is the output of the following snippet?

   #include <iostream>
   using namespace std;
   int op(int i, int j = 1)
   {
      return i * j;
   }
   int op(char a, char b)
   {
      return b - a;
   }
   int op(float x, float y)
   {
      return x / y;
   }
   
   int main()
   {
      cout << op(2) << op('c', 'a') << op(4.f, 2.f);
   }

   • 01-2
   • 2-22
   • 222
   • 2-48

6. What is the output of the following snippet?

   #include <iostream>
   using namespace std;
   
   char do1(char *x)
   {
      return *x;
   }
   
   char *do2(char *y)
   {
      return y;
   }
   
   char *do3(char &z)
   {
      return &z;
   }
   
   int main()
   {
      char sign = '1';
      cout << do1(do2(do3(sign)));
   }

   • 0
   • 2
   • 4
   • 1

7. What is printed on the screen when the following code is run?

   #include <iostream>
   using namespace std;
   
   int main()
   {
      int k = 3;
      if(k > 0){
         if(k != 3)
            k--;
         if(k == 3)
            k++;
         }
       if(k < 0){
         k = 5;
       }
       cout << k;
   }

   • 5
   • 3
   • 2
   • 4

8. What is the output of the following snippet?

   #include <iostream>
   using namespace std;
   
   int main()
   {
       int a = 2, b = a >> 1;
       int c = a >> b;
       int d = a << c;
       int e = d >> d;
       cout << e;
   }

   • 4
   • 1
   • 0
   • 2

9. What is printed on the screen when the following code is run?

   #include <iostream>
   
   using namespace std;
   
   int main()
   {
       int a = 2, b = a >> 1;
       int c = b >> a;
       int d = 1 << c;
       int e = d << d;
       cout << e;
   }

   • 2
   • 4
   • 0
   • 1

10. Which of the following strings represent a legal integer literal?

    (Select two answers.)

    • -111222333
    • b'11001111'
    • 111'222'333
    • x12FE

11. What is printed on the screen when the following code is run?

    #include <iostream>
    #include <string>
    using namespace std;
    
    string replicate(string s = "x", int r =1)
    {
       string t;
       while(r--)
         t += s;
       return t;
    }
    
    int main()
    {
       string pattern = "a";
       cout << replicate(pattern);
    }

    • ax
    • a
    • x
    • xa

12. What is the output of the following snippet?

    #include <iostream>
    #include <vector>
    using namespace std;
    
    int main()
    {
       vector<char> text(5);
     
       char *chr1 = text.data() + 2, *chr2 = chr1  + 2;
       cout << chr2 - text.data();
    }

    • 4
    • 1
    • 3
    • 2

13. What is the output of the following snippet?

    #include <iostream>
    #include <string>
    using namespace std;
    
    int main()
    {
       string s1 = "brick";
       string s2 = "block";
       string s;
    
       s1.swap(s2);
       s2.swap(s);
       s.swap(s2);
       cout << s1;
    }

    • brick
    • It prints an empty string 
    • block
    • Compilation fails

14. What is printed on the screen when the following code is run?

    #include <iostream>
    using namespace std;
    
    int main()
    {
       int a = 0x02, b = 001;
       int c = a ^ b;
       int d = c | a;
       int e = d & 0;
       cout << e;
    }

    • 1
    • 0
    • 2
    • 4

15. What is printed on the screen when the following code is run?

    #include <iostream>
    using namespace std;
    
    int main()
    {
       int i = 1, k = i << 1;
       switch(k){
           case 1: i += 1;
                   break;
           case 2: i += 2;
                   break;
           default: i += 3;
        }
        cout << i;
    }

    • 2
    • 1
    • 3
    • 4

16. What is the output of the following snippet?

    #include <iostream>
    #include <string>
    using namespace std;
    
    int main()
    {
        int i = 2;
        string s = "2";
        cout << s == i;
    }

    • 1
    • Compilation fails 
    • 0
    • The program causes runtime error 

17. What is the output of the following snippet?

    #include <iostream>
    using namespace std;
    
    int main()
    {
        int i = 2;
        float f = 1;
        cout << (static_cast<float>(i) >> 1);
    }

    • 1.0
    • Compilation fails
    • 0
    • 1

18. Which of the following strings represents a legal variable name?

    (Select two answers.)

    • 1myVariable
    • my_variable_1
    • myVariable1
    • my Variable 1

19. What is printed on the screen when the following code is run?

    #include <iostream>
    using namespace std;
    
    int main()
    {
        int i, k = 1;
        for(i = 0; i < 3; i += 2)
            k++;
        cout << k;
    }

    • 3
    • 1
    • 4
    • 2

20. What is the output of the following snippet?

    #include <iostream>
    using namespace std;
    int main()
    {
        short s = 1;
        int i = 2;
        float f = 4;
    
        cout << i/static_cast<float>(s) + i/2 + i/f;
        return 0;
    }

    • 3
    • 4
    • Compilation fails
    • 3.5

21. What is the output of the following snippet?

    #include <iostream>
    using namespace std;
    
    int main()
    {
        string s = "123";
        s.append(s.substr(2)).push_back(s[s.length() - 2]);
        cout << s;
    }

    • 12233
    • 12333
    • 12312323
    • Compilation fails 

22. What is printed on the screen when the following code is run?

    #include <iostream>
    #include <vector>
    using namespace std;
    
    int main()
    {
       vector<double> arr = {1e-1, 1e0, 1e1};
       double *ptr = arr.data() + 2;
       cout << arr[1] - *ptr;
    }

    • -0.9
    • 9
    • -9
    • 0.9

23. What is the output of the following snippet?

    #include <iostream>
    using namespace std;
    double eval(double x)
    {
        return x / (.5 * x);
    }
    void use(double n)
    {
        int v = 1 / n;
        v = eval(v);
        cout << v;
    }
    
    int main()
    {
        use(1.f);
    }

    • 0
    • 4
    • 8
    • 2

24. What is the value of the i variable?

    float x = 1.0 / 5.0;
    int i = x;

    • 5.0
    • 0.20
    • 0
    • 1

25. What is printed on the screen when the following code is run?

    #include <iostream>
    using namespace std;
    
    int main()
    {
        int i = 1, k = i & 0;
        do {
              k++;
              if(k > 1)
                 i = k;
         }while(i < 2);
         cout << k;
    }

    • 3
    • 2
    • 4
    • 1

26. What is the output of the following snippet?

    #include <iostream>
    using namespace std;
    
    int main()
    {
        bool b1 = !true;
        bool b2 = !b1 && false;
        bool b3 = b2 || true;
        if(b3)
           cout << "true";
        else
           cout << "false";
    }

    • true
    • 0
    • false
    • 1

27. What is the value of the k variable?

    int k = 2 % 3 + 5 % 3;

    • 0
    • 1
    • 4
    • 2

28. Which of the following strings represent a legal floating point literal?

    (Select two answers.)

    • 2.2f
    • 1E-1
    • 1.2e1.2
    • 2.2d

29. What is the output of the following snippet?

    #include <iostream>
    using namespace std;
    
    namespace Universe {
        int Galaxy = 1;
    }
    namespace Universe{
        int Planet = Galaxy + 2;
    }
    
    int main()
    {
       Universe::Galaxy *= 2;
       {
         using namespace Universe;
         Planet++;
        }
        cout << Universe::Galaxy << Universe::Planet;
    }

    • Compilation fails 
    • 24
    • 23
    • 42

30. What is the output of the following snippet?

    #include <iostream>
    #include <vector>
    using namespace std;
    
    void swap(float* x, float *y)
    {
        float z = *x;
        *x = *y;
        *y = z;
    }
    
    int main()
    {
         vector<float> t = {3., 2., 1.};
         swap(&t[0], &t[2]);
         cout << t[1];
    }
    
    

    • 2
    • 1
    • 3
    • 0