#include 
     
      using namespace std;class String{public:	String(); //默认的构造函数	~String(){ delete []str; len=0; 	      //cout<<"析构函数执行"<
      
       >(istream &i, String &s)	{		 i>>s.str;	     return i;	}	//当运算符重载函数定义为成员函数时，二元运算符只带一个参数	//将这个函数定义为友元函数即可	friend bool operator<(const String&str1, const String&str2)	{		if(strcmp(str1.str, str2.str) < 0){		    return 1;		}else			return 0;	}	friend bool operator>(const String&str1, const String&str2)	{		if(strcmp(str1.str, str2.str) > 0){		    return 1;		}else			return 0;	}	friend bool operator==(const String&str1, const String&str2)	{		if(strcmp(str1.str, str2.str) == 0){		    return 1;		}else			return 0;	}	//这里是可以修改的	char &operator[](unsigned short int  length);	char  operator[](unsigned short int  length)const;	//复制构造函数	String (const String&r);	//重载赋值运算符=	String &operator=(const String &s);	String operator+(const String&s); //重载相加运算符	void operator+=(const String&s); //重载相加运算符	private:	String(unsigned short int); //构造带值的string	unsigned short int len;	char *str;};//创建一个空的str变量String::String(){    len = 0;	str = new char[1];	str[0] = '\0';};String::String(const char*const ch){	//cout<<"带一个参数的构造函数"<
       
         len){		   return str[len-1]; //返回可见字符的值		}else{		   return str[length];		}};char String::operator[](unsigned short int length)const{	    //cout<<"下标运算符const执行"<
        
          len){		   return str[len-1]; //返回可见字符的值		}else{		   return str[length];		}};String::String (const String&rs){	len = rs.getlen();	str = new char[len+1];	for(int i=0; i