C++ Namespace Aptitude Questions and Answers

1) There are the following statements that are given below, which of them are correct about namespace in C++?

1. A namespace is used to group similar types of classes.
2. Two classes with the same name can be residing in two different namespaces.
3. A namespace can contain functions.
4. All of the above

Options:

1. A
2. B
3. A and B
4. D

2) Which of the following keywords are used for the namespace in C++?

1. namespace
2. namespaces
3. using
4. use

Options:

1. A and B
2. A and C
3. A, B, and C
4. A, B, C, and D

3) Which of the following operator is used to access elements of the namespace?

1. .
2. :
3. ::
4. ->

4) What is the correct output of the given code snippets?

#include <iostream>

using namespace std;

namespace mynamespace {
    private int a = 10;
}

int main()
{
    cout << mynamespace::a << endl;
    return 0;
}

Options:

1. 10
2. Garbage value
3. Syntax error
4. Runtime error

5) What is the correct output of the given code snippets?

#include <iostream>

using namespace std;

namespace mynamespace {
int a = 10;
}

int main()
{
    cout << mynamespace::a << endl;
    return 0;
}

Options:

1. 10
2. Garbage value
3. Syntax error
4. Runtime error

6) What is the correct output of the given code snippets?

#include <iostream>

using namespace std;

int a = 10;

namespace mynamespace {
int* ptr;
}

int main()
{
    mynamespace::ptr = &a;

    cout << *(mynamespace::ptr) << endl;
    return 0;
}

Options:

1. 10
2. Garbage value
3. Syntax error
4. Runtime error

7) What is the correct output of the given code snippets?

#include <iostream>

using namespace std;

int a = 10;

namespace mynamespace {
int& fun()
{
    return a;
}
}

int main()
{
    mynamespace::fun() = 20;

    cout << a << endl;
    return 0;
}

Options:

1. 10
2. 20
3. Garbage values
4. Syntax error

8) What is the correct output of the given code snippets?

#include <iostream>

using namespace std;

namespace mynamespace {
class Sample1 {
public:
    void fun()
    {
        cout << "Sample1 ";
    }
};

class Sample2 {
public:
    void fun()
    {
        cout << "Sample2 ";
    }
};
}

int main()
{
    mynamespace::Sample1 S1;
    mynamespace::Sample2 S2;

    S1.fun();
    S2.fun();

    return 0;
}

Options:

1. Sample1 Sample2
2. Runtime error
3. Garbage values
4. Syntax error

9) What is the correct output of the given code snippets?

#include <iostream>

using namespace std;

namespace mynamespace {
public
class Sample1 {
public:
    void fun()
    {
        cout << "sample1 ";
    }
};

public
class Sample2 {
public:
    void fun()
    {
        cout << "sample2 ";
    }
};
}

int main()
{
    mynamespace::Sample1 S1;
    mynamespace::Sample2 S2;

    S1.fun();
    S2.fun();

    return 0;
}

Options:

1. Sample1 Sample2
2. Garbage value
3. Syntax error
4. Runtime error

10) What is the correct output of the given code snippets?

#include <iostream>

using namespace std;

namespace mynamespace {
class Sample1 {
public:
    void fun()
    {
        cout << "Sample1 ";
    }
};

struct Sample2 {
public:
    void fun()
    {
        cout << "Sample2 ";
    }
};
}

int main()
{
    mynamespace::Sample1 S1;
    mynamespace::Sample2 S2;

    S1.fun();
    S2.fun();

    return 0;
}

Options:

1. Sample1 Sample2
2. Garbage values
3. Syntax error
4. Runtime exception