Math.hpp (Declarations) ◄──── Included by main.cpp & Math.cpp
│
├──► Preprocessor replaces #include with header content
├──► Compiler generates Translation Unit -> Object File (.o/.obj)
└──► Linker binds Object Files into Final Executable (.exe/elf)#ifndef MATH_HPP / #define MATH_HPP / #endif: Standard, universally portable.#pragma once: Supported by all modern compilers, cleaner, less error-prone.#include <iostream>
// Simulated Header Content (Widget.hpp)
#ifndef WIDGET_HPP
#define WIDGET_HPP
class Widget {
private:
int id;
public:
explicit Widget(int widgetId);
void display() const;
};
#endif // WIDGET_HPP
// Simulated Implementation Content (Widget.cpp)
Widget::Widget(int widgetId) : id(widgetId) {}
void Widget::display() const {
std::cout << "[Widget] Active with ID: " << id << "\n";
}
// Simulated main.cpp
int main() {
Widget w(5042);
w.display();
return 0;
}#pragma once or standard include guards at the top of every header file.