gcc vs g++: What's the Difference?

Have you ever thought about the difference between GCC and G++? Well, if I were to answer this in one sentence, it would be "GCC is used to compile C programs whereas G++ is for C++".

But there's a lot more to talk about, such as how you install and use them.

So let's start with the basic introduction.

What is the difference between GCC and G++?

The GCC compiler is used to compile the C programs, whereas the G++ is used for C++ programs. While you could still use GCC to compile C++ program (by using it in gcc -xc++ -lstdc++ -shared-libgcc format, g++ provides a simpler syntax.

Actually, GCC (GNU Compiler Collection) is a super set of various compilers. It has g++ for C++ and GNAT for Ada programming language.

While gcc is capable of compiling C++ programs with help of special flags, you should use g++ instead. The g++ compiler links to standard C++ libraries by default. GCC can also do that but not by default.

Now, let's have a look at the installation.

Installation

Being one of the most essential tools for compiling C and C++ programs in Linux, they both are available in the repositories of all Linux distributions.

Here's how you install it on various Linux distributions:

For Ubuntu/Debian base:

sudo apt install gcc g++

For Fedora/RHEL:

sudo dnf instal gcc g++

For Arch Linux:

sudo pacman -S gcc

(Arch includes G++ in the GCC package itself)

Usage

In this section, I will walk you through how you can compile C and C++ programs using GCC and G++.

To make this guide accessible, I will be using the following C programming code:

#include <stdio.h>

int main() {
    printf("Hello, World!\n");
    return 0;
}

And here's the C++ code:

#include <iostream>

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

They both should print a simple Hello, World! line.

Compile and run C code

To compile a C program, you can use gcc or g++. If you want to use gcc, here's the syntax that you need to follow:

gcc -o my_program my_program.c

Here,

• -o is used to specify the output file
• my_program is where you specify the name of the output file
• my_program.c is where you append the name of the input file

For example, here's how I compiled my hello.c file using the GCC compiler:

gcc -o hello hello.c

To execute any compiled file, add ./ before the name of the compiled file:

./hello

Similarly, if you want to use G++ to compile the C program, use the following:

g++ -o cpp_program cpp_program.c

Here's how I compiled and ran the same hello.c program with G++:

The && operator is used to run multiple commands but the compilation code will be executed first and then the execution will be done.

Compile and run C++ code

To compile C++ code, you have to use the G++ compiler in the following manner:

g++ -o my_code my_code.cpp

Once done, you can run the code using the executable file:

./my_code

For example, here's how I compiled hello.cpp file using the G++ compiler:

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

Next: Here are some important GCC flags

If you are just getting started with the C programming, you are about to use GCC a lot but there are multiple flags that you can use while compiling code.

And here's a detailed guide on important GCC flags:

I hope you will find this guide helpful.