what is the necessity of "namespace" in c++

[Paul M]

#include <iostream.h>
 
int main() {
std::cout<<"Hello World!"<<endl;
return 0;
}

#include <iostream.h>
 
using namespace std;
 
int main() {
cout << "Hello World!" << endl;
return 0;
}

See in the first example how you have to use std::cout well you would have to do that everytime you use methods and members in the std namespace. Where as in the second example you will not have to use std:: before any member

You can make your own namespaces to

namespace shop{
int item;
int price;
}
 
//....
 
using namespace shop;

so you can do

item = 5;

instead of

shop::item = 5;

Hope that helped a little