Bring only a few names into the global namespace
#include <iostream>
// gain access to cout, cin, and hex
using std::cout;
using std::cin;
using std::hex;
int main()
{
int val;
cout << "Enter a number: ";
cin >> val;
cout << "This is your number: ";
cout << hex << val;
return 0;
}Enter a number: 1
This is your number: 1
Use explicit std:: qualification
#include <iostream>
int main()
{
int val;
std::cout << "Enter a number: ";
std::cin >> val;
std::cout << "This is your number: ";
std::cout << std::hex << val;
return 0;
}Enter a number: 1
This is your number: 1
