#include<iostream>
#include<string>
using namespace std;
class String
{
public:
String(){p=NULL;}
String(char *str);
void display();
friend bool operator>(String &string1,String &string2);
private:
char *p;
};
String::String(char *str)
{
p=str;
}
void String::display()
{
cout<<p;
}
bool operator>(String &string1,String &string2)
{
if(strcmp(string1.p,string2.p)>0)
return false;
else return true;
}
int main()
{
String string1("hello!"),string2("book!");
cout<<(string1>string2)<<endl;
return 0;
}
--------------------Configuration: vetor1 - Win32 Debug--------------------
Compiling...
vetor1.cpp
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(24) : error C2248: 'p' : cannot access private member declared in class 'String'
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(12) : see declaration of 'p'
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(24) : error C2248: 'p' : cannot access private member declared in class 'String'
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(12) : see declaration of 'p'
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(31) : error C2593: 'operator >' is ambiguous
Error executing cl.exe.

vetor1.exe - 3 error(s), 0 warning(s)

晕呐没人...自己顶了~~~~急!!!!!!!!!!!

#include<iostream>
#include<string>
using namespace std;
class String
{
public:
String(){p=NULL;}
String(char *str);
void display();
friend bool operator>(String &string2);
private:
char *p;
};
String::String(char *str)
{
p=str;
}
void String::display()
{
cout<<p;
}
bool operator>(String &string2)
{
if(strcmp(p,string2.p)>0)
return false;
else return true;
}
int main()
{
String string1("hello!"),string2("book!");
cout<<(string1>string2)<<endl;
return 0;
}
注意重载的运算符的操作数的个数！

--------------------Configuration: vetor1 - Win32 Debug--------------------
Compiling...
vetor1.cpp
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(10) : error C2805: binary 'operator >' has too few parameters
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(23) : error C2805: binary 'operator >' has too few parameters
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(24) : error C2065: 'p' : undeclared identifier
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(24) : error C2248: 'p' : cannot access private member declared in class 'String'
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(12) : see declaration of 'p'
C:\Program Files\Microsoft Visual Studio\MyProjects\vetor1\vetor1.cpp(31) : error C2676: binary '>' : 'class String' does not define this operator or a conversion to a type acceptable to the predefined operator
Error executing cl.exe.

vetor1.obj - 5 error(s), 0 warning(s)
运行楼上的~~~~

把3楼的改动的两行按下面的改法，变成member function 就可以了。
bool operator>(String &string2);
bool String::operator>(String &string2)

晕，是要像楼上那样再改下才行。

[此贴子已经被作者于2006-3-31 19:56:03编辑过]

那友元函数干嘛不行啊?怎么会不能访问呢error C2248: 'p' : cannot access private member declared in class 'String'

带一个参数的operator overloading对于“>”来说只能是member function。
如果想用friend function的">"就得带两个参数。那样作也可以。

我思考思考再给你说'

谢谢楼上的几位....