Compilation and execution process in C++ - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple C++ program with compilation steps

What is the output of this C++ program when compiled and run?

C++

#include <iostream>
int main() {
    int x = 5;
    int y = 10;
    std::cout << "Sum: " << (x + y) << std::endl;
    return 0;
}

A Sum: 510

B Sum: 15

C Compilation error

D Runtime error

💡 Hint

Remember that + operator adds integers, not concatenates strings.

The program adds integers 5 and 10, printing their sum as 15.

🧠 Conceptual

intermediate

Identify the compilation stage that converts source code to machine code

Which stage in the C++ compilation process converts the source code into machine code?

A Preprocessing

B Linking

C Compilation

D Execution

💡 Hint

Think about when the code is translated into instructions the computer understands.

Compilation translates source code into machine code (object files).

❓ Predict Output

advanced

Output of a program with multiple source files and linking

Given two source files compiled and linked, what is the output when running the program?

C++

// file1.cpp
#include <iostream>
void greet();
int main() {
    greet();
    return 0;
}

// file2.cpp
#include <iostream>
void greet() {
    std::cout << "Hello from linked file!" << std::endl;
}

A Hello from linked file!

B Compilation error: greet undefined

C Runtime error: undefined reference

D No output

💡 Hint

Both files must be compiled and linked together to find greet.

The function greet is defined in file2.cpp and linked to main in file1.cpp, so the output prints correctly.

❓ Predict Output

advanced

What error occurs if a function is declared but not defined?

What error will the compiler or linker produce for this code?

C++

#include <iostream>
void foo();
int main() {
    foo();
    return 0;
}

A Linker error: undefined reference to foo

B Program runs with no output

C Runtime error: segmentation fault

D Compilation error: foo not declared

💡 Hint

Declaration exists but no function body is provided.

The compiler compiles fine but linker fails because foo is declared but not defined.

🧠 Conceptual

expert

Order the stages of C++ program compilation and execution

Select the correct order of stages when compiling and running a C++ program.

A 1,3,2,4

B 2,1,3,4

C 3,2,1,4

D 1,2,3,4

💡 Hint

Think about the order from source code to running program.

The correct order is preprocessing, compilation, linking, then execution.