话不多说，直接撸码，其中原理相信很容易看懂！！！
#include<iostream> using namespace std; class string1 { public: string1();//默认构造函数 string1(int n,char c);//普通构造函数 string1(const char* source);//普通构造函数 string1(const string1& s);//复制构造函数 string1& operator =(char* s);//重载=，实现字符串的赋值 string1& operator = (const string1& s);//重载=，实现对象赋值 ~string1(); char& operator[](int i);//重载[],实现数组运算 const char& operator[](int i)const;//重载[],实现数组运算（对象为常量） string1& operator +=(const string1& s);//与字符相加 string1& operator +=(const char* s);//与对象相加 friend ostream& operator <<(ostream& out,string1& s);//实现输出流 friend istream& operator >>(istream& in,string1& s);//实现输入流 friend bool operator <(const string1& left,const string1& right); friend bool operator >(const string1& left,const string1& right); friend bool operator ==(const string1& left,const string1& right); friend bool operator !=(const string1& left,const string1& right); char* getData(); private: int size; char *data; }; string1::string1() { data = new char[1]; size = 0; *data = '\0'; } string1::string1(int n,char c) { data = new char[n+1]; size = n; char* temp = data; while(n--) { *temp++ = c; //*temp = c;temp++; } *temp = '\0'; } string1::string1(const char* source) { if(source == NULL) { data = new char[1]; *data = '\0'; size = 0; } else { size = strlen(source); data = new char[size+1]; strcpy(data,source); } } string1::string1(const string1 &s) { data = new char[s.size+1]; strcpy(data,s.data); size = s.size; } string1& string1:: operator=(char* s) { if(s != NULL) { delete []data; } size = strlen(s); data = new char[size+1]; strcpy(data,s); return *this; } string1::~string1() { if(data != NULL) { delete []data; data = NULL; size = 0; } } char& string1::operator [](int i) { return data[i]; } const char& string1::operator[] (int i)const { return data[i]; } string1& string1::operator+=(const string1& s) { int len = size+s.size+1; char* temp = data; data = new char[len]; size = len-1; strcpy(data,temp); strcat(data,s.data); delete []data; return *this; } string1::length() { return size; } ostream& operator <<(ostream &out,string1& s) { for(int i=0;i<s.length();i++) { out<<s[i]<<" "; } return out; } istream& operator >>(istream &in,string1 &s) { char p[50]; in.getline(p,50); s = p; return in; } bool operator < (const string1& left,const string1& right) { int i=0; while(left[i]==right[i] && left[i]!=0 && right[i]!= 0) { i++; } return left[i]-right[i] < 0?true:false; }
