What is C++ - Practice Questions & Exercises

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of simple C++ program with variables

What is the output of this C++ program?

C++

#include <iostream>
int main() {
    int a = 5;
    int b = 3;
    std::cout << "Sum: " << a + b << std::endl;
    return 0;
}

A Sum: 8

B Sum: 53

C Sum: 15

D Sum: 2

💡 Hint

Remember that + adds numbers, not strings.

The program adds integers 5 and 3, resulting in 8.

🧠 Conceptual

intermediate

What is the main purpose of C++?

Which option best describes the main purpose of C++?

A A language for system programming and performance-critical applications

B A language mainly for web page styling

C A language only for database queries

D A language used exclusively for mobile app design

💡 Hint

Think about where speed and control over hardware matter.

C++ is widely used for system software, games, and applications needing high performance.

❓ Predict Output

advanced

Output of C++ code with pointers

What is the output of this C++ program?

C++

#include <iostream>
int main() {
    int x = 10;
    int* p = &x;
    *p = 20;
    std::cout << x << std::endl;
    return 0;
}

A 10

B Compilation error

C 20

D Address of x

💡 Hint

Changing value via pointer changes original variable.

Pointer p points to x, so *p = 20 changes x to 20.

🔧 Debug

advanced

Identify the error in this C++ code

What error does this C++ code produce?

C++

#include <iostream>
int main() {
    int a = 5;
    int b = 0;
    std::cout << a / b << std::endl;
    return 0;
}

A No error, outputs 0

B Syntax error: missing semicolon

C Type error: incompatible types

D Division by zero runtime error

💡 Hint

Dividing by zero is not allowed.

Dividing an integer by zero causes a runtime error or crash.

🚀 Application

expert

What is the output of this C++ code using classes?

What is the output of this program?

C++

#include <iostream>
class Counter {
public:
    int count = 0;
    void increment() { count++; }
};
int main() {
    Counter c1, c2;
    c1.increment();
    c2.increment();
    c2.increment();
    std::cout << c1.count << " " << c2.count << std::endl;
    return 0;
}

A 2 1

B 1 2

C 0 0

D Compilation error

💡 Hint

Each object has its own count variable.

c1 increments once, c2 increments twice, so output is '1 2'.