Compilation and execution process in C++

Introduction

We need to turn the code we write into instructions the computer can understand and run.

When you write a C++ program and want to run it on your computer.

When you want to check if your code has mistakes before running it.

When you want to make your program faster by turning it into machine code.

When you want to share your program with others without sharing the source code.

Syntax

C++

g++ filename.cpp -o outputname
./outputname

g++ is the compiler that turns C++ code into a program.

The -o option names the output program.

Examples

Compile hello.cpp into a program called hello and run it.

C++

g++ hello.cpp -o hello
./hello

Compile with warnings enabled to catch possible mistakes.

C++

g++ -Wall program.cpp -o program
./program

Sample Program

This simple program prints "Hello, world!" to the screen.

First, you compile it with g++ filename.cpp -o filename, then run the program with ./filename.

C++

#include <iostream>

int main() {
    std::cout << "Hello, world!" << std::endl;
    return 0;
}

Important Notes

Compilation turns your code into machine language the computer understands.

Execution runs the machine code to perform the program's tasks.

If there are errors in your code, the compiler will show messages to help you fix them before running.

Summary

Compilation changes your C++ code into a program the computer can run.

Execution runs the compiled program to do what you wrote.

You must compile before you can execute your C++ program.