CPA – Programming Essentials in C++ Module 4 Exam Answers

What is the output of the following snippet?

#include <iostream>

using namespace std;

int main()

{

    int *it[3];

    for(int i = 0; i < 3; i++) {

        it[i] = new int [i + 1];

        for(int j = 0; j < i + 1; j++)

            it[i][j] = 10 * i + j;

    }

    cout << it[2][2];

    for(int i = 0; i < 3; i++)

        delete [] it[i];

}

• 11
• Compilation fails
• 33
• 22

What is the output of the following snippet?

#include <iostream>

using namespace std;

int main()

{

    short s = 1;

    int i = 2;

    float f = 4.4;

    double d = 6.6;

    cout << i/static_cast<float>(s) + int(f)/i + (long)d/s;

    return 0;

}

• 8.0
• Compilation fails
• 10
• 8.8

What is the output of the following snippet?

#include <iostream>

#include <vector>

using namespace std;

int main()

{

    vector<float *> ft = { new float[3], new float[3], new float[3] };

    float *p = nullptr;

    for(int i = 0; i < 3; i++) {

        p = ft[i];

        *p = p[1] = *(p + 2) = 10 * i;

    }

    cout << ft[1][1];

    delete [] ft[0];

    delete [] ft[1];

    delete [] ft[2];

}

• 10
• 20
• Compilation fails
• 30

What is the output of the following snippet?

#include <iostream>

using namespace std;

namespace S {

    int A = 1;

}

namespace S {

    int B = A + 2 ;

}

int main()

{

    S::A = S::A + 1;

    {

        using namespace S;

        ++B;

    }

    cout << S::B << S::A;

    return 0;

}

• 22
• 32
• 42
• Compilation fails

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

int main()

{

    string s = “ABC”;

    for(int i = 1; i < s.length(); i += 2)

        s[i – 1] = s[i] + ‘a’ – ‘A’;

    cout << s;

}

• bBc
• bBC
• Compilation fails
• aAcC

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

int main()

{

    string s1 = “aleph”;

    string s2 = “alpha”;

    string s;

    s1.swap(s2);

    s2.swap(s);

    s.swap(s2);

    cout << s2;

}

• alpha
• Compilation fails
• aleph
• It prints an empty string

What is the output of the following snippet?

#include <iostream>

using namespace std;

    int main()

{

    string s1 = “Ab”;

    string s2 = “Abc”;

    cout << s1.compare(s1);

}

• Compilation fails
• 1
• -1
• 0

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

int main()

{

    string s = “AB”;

    s.append(s).push_back(s[s.length() – 1]);

    cout << s;

}

• ABABA
• ABAB
• ABABB
• Compilation fails

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

    int main()

{

    string s = “a”;

    cout << s  << “b” + “c”;

}

• a
• ab
• Compilation fails
• abc

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

  int main()

{

    string s = “0123”;

    cout << s.substr(1,3).substr(2).substr();

}

• It prints an empty string
• 3
• 123
• Compilation fails

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;

}

• 2
• 2
• 4
• Compilation fails

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;

}

• 2
• 2
• 4
• Compilation fails

What is the output of the following snippet?

#include <iostream>

#include <string>

#include <vector>

using namespace std;

int main()

{

    vector<string> t = { “alpha”, “beta”, “gamma” };

    int *cnt = new int[3], *p = &cnt[0];

    for(int i = 0; i < t.size(); i++)

        *p++ = t[i].length();

    cout << cnt[0] << cnt[1] << cnt[2];

    delete [] cnt;

}

• 012
• 545
• 111
• Compilation fail

What is the output of the following snippet?

#include <iostream>

using namespace std;

   int main()

{

    short s = 1;

    int i = 2;

    float f = 4.4;

    double d = 8.8;

    cout << s/i + f/i + d/s;

}

• 11
• Compilation fails
• 6.6
• 4.4

What is the output of the following snippet?

#include <iostream>

using namespace std;

namespace S1 {

    int A = 1;

}

namespace S2  {

    int A = 2 ;

}

int main()

{

    { using namespace S1;

        S2::A = A + 1;

    }

    { using namespace S2;

        S1::A = A + 1;

    }

    cout << S1::A << S2::A;

}

• Compilation fails
• 32
• 33
• 23

What is the output of the following snippet?

include <iostream>

using namespace std;

    int main()

{

    int i = 2;

    float f = 5.8;

    f = static_cast<int>(f);

    i = static_cast<float>(i);

    cout << f/i;

}

• 1
• Compilation fails
• 2.5
• 3

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

int main()

{

    string s = “a”;

    cout << s + “b” + “c”;

}

• abc
• ab
• Compilation fails
• a

What is the output of the following snippet?

#include <iostream>

#include <string>

using namespace std;

int main() {

    string s1 = “ab”;

    string s2 = “Abc”;

    if(s1 > s2)

        cout << “yes”;

    else

        cout << “NO”;

}

• Compilation fails
• yes
• It prints nothing
• NO

What is the output of the following snippet?

#include <iostream>

namespace SpaceA {

    int A;

}

namespace SpaceB {

    int A;

}

using namespace SpaceA, SpaceB;

int main()

{

    SpaceA::A = SpaceB::A = 1;

    std::cout << A + 1;

}

• Compilation fails
• 1
• 0
• 2

What is the output of the following snippet?

#include <iostream>

using namespace std;

int main() {

    string s1 = “1”;

    string s2 = “12”;

    cout << s1.compare(s2);

}

• –1
• 0
• 1
• Compilation fails

What is the output of the following snippet?

#include <iostream>

using namespace std;

int main()

{

    int i = 2;

    float f = 4.4;

    cout << f % static_cast<float>(i);

}

• 0
• 2
• 0.2
• Compilation fails