[Ryan2]

Could someone please tell me what the pros and cons are of using

using namespace std;

and not using it.

I do not really know how i cant use it (if you know what i mean) although i have done a few tests and relised that without using namespace std i must write.

#include <iostream>

int main()
{

std::cout << "Hello world"<<std:: endl;

return 0;
}

basically i just want to know if i should use "using namespace std" and if i shouldnt, where should i implement "std::" and it would really help me if someone could explain why i should do this. I heard that "using namespace std;" "pollutes" your code.........

greatly appreciated. thank you.

This post has been edited by Ryan2: 09 March 2009 - 10:59 AM

[KYA]

If its a small program and something relatively simple, then there really isn't any harm is importing the entire std namespace. It also saves typing. however, the problem arises when you have a larger program with numerous namespaces, perhaps a few you've made yourself, etc... you don't want to pollute the namespace by importing the entire std one. In that case you can import just what you want to use:

using std::cout;
using std::endl;
//etc...

[Ryan2]

KYA, on 9 Mar, 2009 - 10:05 AM, said:

If its a small program and something relatively simple, then there really isn't any harm is importing the entire std namespace. It also saves typing. however, the problem arises when you have a larger program with numerous namespaces, perhaps a few you've made yourself, etc... you don't want to pollute the namespace by importing the entire std one. In that case you can import just what you want to use:

using std::cout;
using std::endl;
//etc...

I see, i didnt think of it like that. That makes sense, thanks alot.

[sparkart]

using namespace xxxx;

will negate the purpose of namespaces especially in bigger projects.