C++ first class

#include
using std::cout;//identifier(名字，标示符) scope(作用域)
using std::cin;// using directive(using指令)
using std::endl;
//using namespace std;//名字空间(namespace) name clashing(名字冲突)

int main()
{
	int x = 10;
	float f = 0.23;
	char s[]="Ligang";
	std::cout<<"Hello,"
		<>s>>x[0];
	cout<