代码

#include 
#include using namespace std;class My_string
{
private:char* cstr;int len;
public:My_string():cstr(NULL),len(0)                     //无参构造{}My_string(const char* str)      //有参构造{this->len = strlen(str);this->cstr = new char[(this->len)+1];strcpy(this->cstr,str);}My_string(const My_string &other)//拷贝构造函数{this->len = other.len;this->cstr = new char;strcpy(this->cstr,other.cstr);}~My_string()                     //析构函数{delete this->cstr;}bool empty()                     //判断是否为空{return this->len == 0 ? true : false;}int size()                       //返回字符串的长度{return this->len;}char &at(int index)              //定位函数{return *(this->cstr+index);}char* c_str()                     //转化为C风格的字符串{return this->cstr;}};int main()
{My_string s1 = "hello";//e 0 5 hellocout << s1.at(1) << " " << s1.empty() << " " << s1.size() << " " << s1.c_str() << endl;My_string s2(s1);//hellocout << s2.c_str() << endl;My_string s3;//1cout << s3.empty() <c_str() << " " << s4->empty() << endl;delete s4;//e 0 5 hellocout << s1.at(1) << " " << s1.empty() << " " << s1.size() << " " << s1.c_str() << endl;return 0;
}

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