[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;


}...