#include <iostream>
using namespace std;
class Time
{
 public:
 Time( ){minute=0;sec=0;} //默认构造函数
 Time(int m,int s):minute(m),sec(s){ } //构造函数重载
 Time operator++( ); //声明运算符重载函数
 void display( ){cout<<minute<<":"<<sec<<endl;} //定义输出时间函数
 private:
 int minute;
 int sec;
};
Time Time::operator++( ) //定义运算符重载函数
{
 if(++sec>=60)
 {
  sec-=60; //满60秒进1分钟
  ++minute;
 }
 return *this; //返回当前对象值
}
int main( )
{
 Time time1(34,0);
 for (int i=0;i<61;i++)
 {
  ++time1;
  time1.display( );
 }
 return 0;
}

34:1
34:2
┆
34:59
35:0
35:1 (共输出61行)

#include <iostream>
using namespace std;
class Time
{
 public:
 Time( ){minute=0;sec=0;}
 Time(int m,int s):minute(m),sec(s){}
 Time operator++( );//声明前置自增运算符“++”重载函数
 Time operator++(int);//声明后置自增运算符“++”重载函数
 void display( ){cout<<minute<<":"<<sec<<endl;}
 private:
 int minute;
 int sec;
};
Time Time::operator++( )//定义前置自增运算符“++”重载函数
{
 if(++sec>=60)
 {
  sec-=60;
  ++minute;
 }
 return *this;//返回自加后的当前对象
}
Time Time::operator++(int)//定义后置自增运算符“++”重载函数
{
 Time temp(*this);
 sec++;
 if(sec>=60)
 {
  sec-=60;
  ++minute;
 }
 return temp; //返回的是自加前的对象
}
int main( )
{
 Time time1(34,59),time2;
 cout<<" time1 : ";
 time1.display( );
 ++time1;
 cout<<"++time1: ";
 time1.display( );
 time2=time1++; //将自加前的对象的值赋给time2
 cout<<"time1++: ";
 time1.display( );
 cout<<" time2 :";
 time2.display( ); //输出time2对象的值
}

time1 : 34:59(time1原值)
++time1: 35:0 (执行++time1后time1的值)
time1++: 35:1 (再执行time1++后time1的值)
time2 : 35:0 (time2保存的是执行time1++前time1的值)

#include <iostream>
using namespace std;
class String
{
 public:
 String( ){p=NULL;} //默认构造函数
 String(char *str); //构造函数
 void display( );
 private:
 char *p;//字符型指针,用于指向字符串
};
String::String(char *str) //定义构造函数
{p=str;} //使p指向实参字符串
void String::display( ) //输出p所指向的字符串
{cout<<p;}
int main( )
{
 String string1("Hello"),string2("Book");
 string1.display( );
 cout<<endl;
 string2.display( );
 return 0;
}

Hello
Book

#include <iostream>
#include <string>
using namespace std;
class String
{
  public:
  String( ){p=NULL;}
  String(char *str);
  friend bool operator>(String &string1,String &string2);//声明运算符函数为友元函数
  void display( );
  private:
  char *p;//字符型指针,用于指向字符串
};
String::String(char *str)
{p=str;}
void String::display( ) //输出p所指向的字符串
{cout<<p;}
bool operator>(String &string1,String &string2)//定义运算符重载函数
{
  if(strcmp(string1.p,string2.p)>0)
   return true;
  else return false;
}
int main( )
{
  String string1("Hello"),string2("Book");
  cout<<(string1>string2)<<endl;
}

 friend bool operator> (String &string1, String &string2);
 friend bool operator< (String &string1, String &string2);
 friend bool operator==(String &string1, String& string2);

bool operator>(String &string1,String &string2) //对运算符“>”重载
{
 if(strcmp(string1.p,string2.p)>0)
  return true;
 else
  return false;
}
bool operator<(String &string1,String &string2) //对运算符“<”重载
{
 if(strcmp(string1.p,string2.p)<0)
  return true;
 else
  return false;
}
bool operator==(String &string1,String &string2) //对运算符“==”重载
{
 if(strcmp(string1.p,string2.p)==0)
  return true;
 else
  return false;
}

int main( )
{
 String string1("Hello"), string2("Book"), string3("Computer");
 cout<<(string1>string2)<<endl; //比较结果应该为true
 cout<<(string1<string3)<<endl; //比较结果应该为false
 cout<<(string1==string2)<<endl; //比较结果应该为false
 return 0;
}

1
0
0

#include <iostream>
using namespace std;
class String
{
 public:
 String( ){p=NULL;}
 String(char *str);
 friend bool operator>(String &string1, String &string2);
 friend bool operator<(String &string1, String &string2);
 friend bool operator==(String &string1, String &string2);
 void display( );
 private:
 char *p;
};
String::String(char *str)
{p=str;}
void String::display( ) //输出p所指向的字符串
{cout<<p;}
bool operator>(String &string1, String &string2)
{
 if(strcmp(string1.p, string2.p)>0)
  return true;
 else
  return false;
}
bool operator<(String &string1, String &string2)
{
 if(strcmp(string1.p, string2.p)<0)
  return true;
 else
  return false;
}
bool operator==(String &string1, String &string2)
{
 if(strcmp(string1.p, string2.p)==0)
  return true;
 else
  return false;
}
void compare(String &string1, String &string2)
{
 if(operator>(string1, string2)==1)
  {string1.display( );cout<<">";string2.display( );}
 else
  if(operator<(string1, string2)==1)
   {string1.display( );cout<<"<";string2.display( );}
  else
   if(operator==(string1, string2)==1)
   {string1.display( );cout<<"=";string2.display( );}
 cout<<endl;
}
int main( )
{
 String string1("Hello"), string2("Book"), string3("Computer"), string4("Hello");
 compare(string1, string2);
 compare(string2, string3);
 compare(string1, string4);
 return 0;
}

Hello>Book
Book<Computer
Hello==Hello