C++ const Keyword Aptitude Questions and Answers

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

1. The const keyword is used to create constants. That's value cannot be changed during program execution.
2. The constant created in C++ must be initialized at the time of declaration.
3. The member initializer list is used to initialize const members of the class.
4. All the above.

Options:

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

2) In C++, the const keyword can be used with?

1. Variables
2. Member functions
3. Objects
4. Pointers

Options:

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

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

#include <iostream>
using namespace std;

int main()
{
    const int A;

    A = 10;

    cout << A << endl;

    return 0;
}

Options:

1. 10
2. Compile-time error
3. Runtime error
4. Linker error

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

#include <iostream>
using namespace std;

const int fun()
{
    return 10;
}

int main()
{
    const int val = fun();

    cout << val;

    return 0;
}

Options:

1. 10
2. Compile-time error
3. Runtime error
4. Linker error

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

#include <iostream>
using namespace std;

int main()
{
    const int A;

    int* p = &A;

    *p = 20;

    cout << A << endl;

    return 0;
}

Options:

1. 10
2. Compile-time error
3. Vary to the compiler to compiler
4. Linker error

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

#include <iostream>
using namespace std;

int main()
{
    int A = 10;

    int* const p = &A;

    *p = 20;

    cout << A << endl;

    return 0;
}

Options:

1. 10
2. 20
3. Compile-time error
4. Vary to the compiler to compiler

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

#include <iostream>
using namespace std;

int main()
{
	int A=10;
	
	int const *p = &A;
	
	*p = 20;
	
	cout<<A<<endl;
	
	return 0;
}

Options:

1. 10
2. 20
3. Compile-time error
4. Vary to the compiler to compiler

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

#include <iostream>
using namespace std;

int main()
{
	int A=10;
	
	const int *p = &A;
	
	*p = 20;
	
	cout<<A<<endl;
	
	return 0;
}

Options:

1. 10
2. 20
3. Compile-time error
4. Vary to the compiler to compiler

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

#include <iostream>
using namespace std;

class Sample
{
	const int X;
	const int Y;
	
	public:
	Sample()
	{
		 X=10;
		 Y=20;
	}
	
	void print()
	{
		cout<<X<<" "<<Y<<endl;
	}
};

int main()
{
	Sample S;
	
	S.print();
	
	return 0;
}

Options:

1. 10 20
2. Compile-time error
3. Vary to the compiler to compiler
4. Runtime error

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

#include <iostream>
using namespace std;

class Sample
{
	const int X;
	const int Y;
	
	public:
	Sample(): X(10),Y(20)
	{}
	
	void print()
	{
		cout<<X<<" "<<Y<<endl;
	}
};

int main()
{
	Sample S;
	
	S.print();
	
	return 0;
}

Options:

1. 10 20
2. Compile-time error
3. Vary to the compiler to compiler
4. Runtime error

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

#include <iostream>
using namespace std;

class Sample
{
	int X;
	int Y;
	
	public:
	Sample()
	{
		 X=10;
		 Y=20;
	}
	
	const void setVal()
	{
		X=15;
		Y=25;
	}
	
	void print()
	{
		cout<<X<<" "<<Y<<endl;
	}
};

int main()
{
	Sample S;
	
	S.setVal();
	S.print();
	
	return 0;
}

Options:

1. 10 20
2. 15 25
3. Vary to the compiler to compiler
4. Compile-time error

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

#include <iostream>
using namespace std;

class Sample
{
	int X;
	int Y;
	
	public:
	Sample()
	{
		 X=10;
		 Y=20;
	}
	
	void setVal() const
	{
		X=15;
		Y=25;
	}
	
	void print()
	{
		cout<<X<<" "<<Y<<endl;
	}
};

int main()
{
	Sample S;
	
	S.setVal();
	S.print();
	
	return 0;
}

Options:

1. 10 20
2. 15 25
3. Vary to the compiler to compiler
4. Compile-time error

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

#include <iostream>
using namespace std;

class Sample
{
	int X;
	int Y;
	
	public:
	Sample()
	{
		 X=10;
		 Y=20;
	}
	
	void setVal()
	{
		X=15;
		Y=25;
	}
	
	void print()
	{
		cout<<X<<" "<<Y<<endl;
	}
};

int main()
{
	const Sample S;
	
	S.setVal();
	S.print();
	
	return 0;
}

Options:

1. 10 20
2. 15 25
3. Vary to the compiler to compiler
4. Compile-time error

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

#include <iostream>
using namespace std;

const int fun(int a, int b)
{
	return a+b;
}

int main()
{
	const int val = fun(10,20);
	
	cout<<val;
	
	return 0;
}

Options:

1. 30
2. Runtime error
3. Vary to the compiler to compiler
4. Compile-time error

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

#include <iostream>
using namespace std;

void fun(const int a, int b)
{
	a=10;
	b=20;
}

int main()
{
	int A = 10;
	int B = 10;
	
	fun(A,B);
	
	cout<<A<<" "<<B;
	
	return 0;
}

Options:

1. 10 20
2. Runtime error
3. Vary to the compiler to compiler
4. Compile-time error