CPA – Programming Essentials in C++ Chapter 1 Module 3

Question 1:

What is the output of the following snippet?

using namespace std;

float Float(float x)

{

    return 2 * x / (.5 * x);

}

void Void(int n)

{

    float v = n;

    v = Float(v);

    cout << v;

}

int main()

{

    Void(1);

}

Answer:

4

Question 2:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int main() 

{

    int *val = new int;

    *val = sizeof(val) / sizeof(int *);

    int *tab = new int[*val];

    tab[0] = *val;

    delete val;

    cout << *tab;

    delete [] tab;

}

Answer:

1

Question 3:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int fun(float a, float b) 

{

    return a / b;

}

int main() 

{

    cout << fun(fun(1., 2.),fun(2., 1.));

}

Answer:

0

Question 4:

What is the output of the following snippet?

#include <iostream>

#include <vector>

using namespace std;

int f1(int *a) 

{

    return *a + 1;

}

int *f2(int *a) 

{

    return a + 1;

}

int *f3(int &a) 

{

    return &a + 1;

}

int main() 

{

    vector<int> t = {0, 1, 2, 3};

    cout << f1(f3(*f2(t.data())));

}

Answer:

3

Question 5:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int f1(int a) 

{

    return ++a;

}

int f2(int &a) 

{

    return ++a;

}

int f3(int *a) 

{

    return *a + 1;

}

int main() 

{

    int value = 2;

    cout << f1(value);

    cout << f2(value);

    cout << f3(&value);

}

Answer:

334

Question 6:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int fun(int a, int b) 

{

    return a + b;

}

int fun(int a, char b) 

{

    return b - a;

}

int fun(float a, float b) 

{

    return a * b;

}

int main() 

{

    cout << fun(1,0) << fun('a','c') << fun(2.f,2.f);

}

Answer:

124

Question 7:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int fun(long a, long b = 1) 

{

    return a << b;

}

int fun(int a, char b = 'z') 

{

    return b - a;

}

int fun(float a, float b = 0) 

{

    return a * b;

}

int main() 

{

    cout << fun(1L) << fun('x') << fun(2e0f);

}

Answer:

220

Question 8:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int f1(int *a) 

{

    return *a;

}

int *f2(int *a) 

{

    return a;

}

int *f3(int &a) 

{

    return &a;

}

int main() 

{

    int value = 2;

    cout << f1(f2(f3(value)));

}

Answer:

2

Question 9:

What is the output of the following snippet?

#include <iostream>

using namespace std;

struct S {

    float *f;

};

void make(S *p, float x = 10) 

{

    float *f = new float; 

    *f = sizeof(*f) / sizeof(float) * 10;

    p->f = f;

}

int main() 

{

    S *ss = new S;

    make(ss);

    cout << *(*ss).f;

    delete ss->f;

    delete ss;

}

Answer:

10

Question 10:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int fun(long a) 

{

    return a / a;

}

int fun(int a) 

{

    return 2 * a;

}

int fun(double a = 3.0) 

{

    return a;

}

int main() {

    cout << fun(1000000000L) << fun (1L) << fun(1.f);

}

Answer:

111

Question 11:

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

string fun(string t, string s = "x", int r = 1) 

{

    while(--r)

        s += s;

    t = t + s;

    return s;

}

int main() 

{

    string name = "a";

    cout << fun(name);

    cout << name;

}

Answer:

Xa

Question 12:

What is the output of the following snippet?

#include <iostream>

#include <vector>

using namespace std;

int fun(int* t) 

{

    t[0] += t[1];

    return t[0];

}

int main() 

{

    vector<int> t = { 5,6,7 };

    cout << fun(&t[1]);

    cout << t[0];

}

Answer:

135

Question 13:

What is the output of the following snippet?

#include <iostream>

#include <vector>

using namespace std;

int main() 

{

    vector<float> f(2);

    float *p1 = f.data(), *p2 = p1 + 1;

    cout << (p2 - p1) / sizeof(float);

}

Answer:

0

Question 14:

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

string fun(string &t, string s = "", int r = 1) 

{

    while(--r)

        s += s;

    t = t + s;

    return s;

}

int main() 

{

    string name = "x";

    cout << fun(name, name);

    cout << name;

}

Answer:

Xxx

Question 15:

What is the output of the following snippet?

#include <iostream>

#include <vector>

using namespace std;

int main() 

{

    vector<int> tab = { 1, 2, 4 };

    int *p1 = &tab[0], *p2 = p1 + 2;

    tab[1] = p2[-1] + *p1;

    cout << tab[1];

}

Answer:

3

Question 16:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int main() 

{

    float x = 3.14, *p = &x;

    p[0] = ++x;

    cout << x;

}

Answer:

4.14

Question 17:

What is the output of the following snippet?

#include <iostream>

#include <vector>

using namespace std;

int main() 

{

    vector<int> t = { 3, 2, 1 };

    int *ptr = t.data() + 1;

    (*(ptr + 1))++;

    (*(ptr - 1))++;

    cout << t[0] << t[1] << t[2];

}

Answer:

422

Question 18:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int fun(int p1 = 1, int p2 = 1) 

{

    return p2 + p1;

}

int main() 

{

    cout << fun(fun(), fun(2));

}

Answer:

5

Question 19:

What is the output of the following snippet?

#include <iostream>

using namespace std;

int *make(int v) 

{

    int *p = new int;

    *p = v + 1;

    return p;

}

int *play(int &v) 

{

    cout << ++v;

    return &v;

}

void remove(int *v) 

{

    delete v;

}

int main() 

{

    remove(play(*make(3)));

}

Answer:

5

Question 20:

What is the output of the following snippet?

#include <iostream>

using namespace std;

float fun(float arg) 

{

    return arg * arg + arg + 1;

}

int main() 

{

    cout << fun(fun(1.0));

}

Answer:

13