定义一个字符串类重载运算比较运算

 1 #define NULL 0
 2 #include <iostream>
 3 #include <string.h>
 4 /* run this program using the console pauser or add your own getch, system("pause") or input loop */
 5 using namespace std;
 6 class String
 7 {
 8     public:
 9         String(){
10             p=NULL;
11         }
12         String(char *str);
13         friend bool operator>(String &string1,String &string2);
14         void display();
15     private:
16         char *p;
17 };
18 
19 String::String(char *str)
20 {
21     p=str;
22 }
23 
24 void String::display()
25 {
26     cout<<p;
27 }
28 
29 bool operator>(String &string1,String &string2)
30 {
31     if(strcmp(string1.p,string2.p)>0)
32     return true;
33     else return false;
34 }
35 int main(int argc, char** argv) {
36     String string1("Hello"),string2("Book");
37     cout<<(string1>string2)<<endl;
38 }