[c/c++]宏定义，#，##

# —— 字符串

##——连接两个参数


#include
<iostream>


using
namespace std;




#define TEST(pid) (cout<<para##pid<<endl);


#define TEST2(p) (cout<<#p<<endl);


int main()




{



int para3
= 3;



int para2
= 2;


TEST(2);
//<==>cout<<para2<<endl;


TEST(3);
//<==>cout<<para3<<endl;




TEST2(test)
//<==>cout<<"test"<<endl;


TEST2("test2");
//<==>cout<<""test2""<<endl;


system("pause");



return
0;


}