What are C++ namespaces? 📛

C++ why you shouldn't "using namespace std"
namespaces tutorial example explained

#using #namespace #std

[BroCodez]

#include <iostream>
namespace first{
int x = 1;
}
namespace second{
int x = 2;
}
int main() {

int x = 0;

std::cout << x;
std::cout << first::x;
std::cout << second::x;

return 0;
}

[Blackilykat]

thank you for the warning about `using namespace std`, my teacher is telling us to always use that when writing in c++

[spamfilter]

Thabk you for going over "using namespace std" and why it shouldn't be used. So many tutorials start wirh it and never explain to people what it is, and why they are using it.

[GaneshKumatole]

Thank you so much for this one ..

NOW I GET THIS 🔥🔥👍👍

[curiouslife]

Bro. You are great. Love you from the Core of my Heart ❤️❤️❤️❤️❤️❤️❤️

[TheUninstaller]

finally.. thank you for making it make sense

[ryanalnaser]

whatever anything before or after whatever anything I do or did or anything

[learningXode-NG]

its some what similiar to different object with same class

[aon]

So I tried using this code

#include <iostream.

namespace first {
int x = 10;
}

int main(){
using namespace first;

int x = 5;

std::cout << x << "\n";

return 0;
}


Quick question: Does the variable get redefined in int main when you use using namespace first despite having the same variable already defined in the namespace?

[stiz]

#include <iostream>
int main (){
std::string << comment = "im first lol" ;
std::cout << comment;
return 0;
}

[gusgus]

namespace cnts
{
// namespace for constants
const int DAYS_PER_WEEK = 7;
const int WEEKS_PER_MONTH = 4;
const int MONTHS_PER_YEAR = 12;
const int DAYS_PER_YEAR = 365;
}

namespace msgs
{
// namespace for messages
std::string hello = "Hello there!";
std::string welcome = "Welcome!";
std::string gameOver = "GAME OVER!";
}

int main()
{
int days_per_month = cnts::DAYS_PER_WEEK * cnts::WEEKS_PER_MONTH;
std::cout << "There are " << days_per_month << " days in one month." << std::endl;

std::cout << msgs::welcome << " Gus!\n";
std::cout << msgs::gameOver << std::endl;
std::cout << msgs::hello << std::endl;

return 0;
}