C++ is a powerful programming language widely used in system/software development, game development, and high-performance computing. Mastery of C++ requires not only understanding core concepts but also practicing various problem-solving techniques. Multiple-choice questions (MCQs) are an excellent way to test knowledge and reinforce learning. This article provides a comprehensive overview of key C++ MCQs to help you sharpen your skills and prepare for exams or interviews.
Understanding C++ Basics
What is the output of the following code?
cpp
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#include <iostream>
using namespace std;
int main() {
int x = 10;
int y = 5;
cout << x + y << endl;
return 0;
}
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- A) 10
- B) 5
- C) 15
- D) Compilation Error
- Answer: C) 15
Explanation: This code performs basic arithmetic operations and outputs the sum of x and y, which is 15. - Which of the following is a valid C++ data type?
- A) integer
- B) bool
- C) float32
- D) char32
- Answer: B) bool
Explanation: C++ supports bool, int, float, and char as fundamental data types. float32 and char32 are not standard C++ types.
Advanced Concepts in C++
What will be the output of the following code?
cpp
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#include <iostream>
using namespace std;
int main() {
int x = 10;
int y = 20;
cout << (x > y ? x : y) << endl;
return 0;
}
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- A) 10
- B) 20
- C) 30
- D) Compilation Error
- Answer: B) 20
Explanation: The ternary operator x > y ? x : y evaluates to y because x is not greater than y. - What does the keyword ‘virtual’ indicate in C++?
- A) A method that can be overridden in a derived class
- B) A method that cannot be overridden in a derived class
- C) A method that can be executed asynchronously
- D) A method that is private
- Answer: A) A method that can be overridden in a derived class
Explanation: The virtual keyword allows a method in a base class to be overridden in a derived class, enabling polymorphism.
Object-Oriented Programming (OOP)
- Which of the following is true about constructors in C++?
- A) Constructors can be private.
- B) Constructors are inherited by derived classes.
- C) Constructors do not have a return type.
- D) Constructors can be declared with the static keyword.
- Answer: A) Constructors can be private. & C) Constructors do not have a return type.
Explanation: Constructors can be private and are not inherited by derived classes. They also do not have a return type. - What is the purpose of the ‘this’ pointer in C++?
- A) It points to the base class of the current object.
- B) It points to the address of the current object.
- C) It is used to delete objects.
- D) It references the static data members of a class.
- Answer: B) It points to the address of the current object.
Explanation: The this pointer is used within a class to refer to the object itself and access its members.
Advanced C++ Topics
What will be the output of the following code snippet?
cpp
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#include <iostream>
using namespace std;
int main() {
int arr[] = {1, 2, 3, 4, 5};
cout << *(arr + 2) << endl;
return 0;
}
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- A) 1
- B) 2
- C) 3
- D) 4
- Answer: C) 3
Explanation: The expression *(arr + 2) points to the third element of the array, which is 3. - Which of the following is true about destructors in C++?
- A) A destructor can have parameters.
- B) A destructor has the same name as the class, preceded by a tilde (~).
- C) Destructors are not automatically called when an object goes out of scope.
- D) A class can have multiple destructors.
- Answer: B) A destructor has the same name as the class, preceded by a tilde (~).
Explanation: A destructor in C++ has the same name as the class but is preceded by a tilde ~. It is automatically called when an object goes out of scope.
Conclusion
Mastering C++ requires a solid understanding of its syntax and concepts. Using MCQs to test your knowledge can help reinforce learning and identify areas that need further study. By regularly practicing these questions, you can build a strong foundation in C++ and enhance your problem-solving skills. Whether you’re preparing for exams or interviews, these MCQs will guide you in assessing your proficiency and improving your C++ programming abilities.