Question

C++中include <iostream>和include <iostream.h>有什么区别。

这个程序不加.h为什么有错
#include <iostream.h>
class test{
private:
int i;
float f;
char ch;
public:
test(int a=0,float b=0,char c='\0'){i=a;f=b;ch=c;}
friend ostream & operator<<(ostream&,test);
friend istream & operator>>(istream&,test&);
};

ostream & operator<<(ostream&stream,test obj)
{
stream<<obj.i<<",";
stream<<obj.f<<",";
stream<<obj.ch<<endl;
return stream;
}

istream & operator>>(istream&t_stream,test&obj)
{
t_stream>>obj.i;
t_stream>>obj.f;
t_stream>>obj.ch;
return t_stream;
}

void main()
{
test A(45,8.5,'W');
operator<<(cout,A);
test B,C;
cout<<"Input as i f ch:";
operator >> (cin,B);operator >> (cin,C);
operator << (cout,B); operator << (cout,C);
}

Answer 1

不加.h用#include <iostream>
你加上using namespace std;告诉程序你用的都是这个名字空间的名字也就可以了