C + + "String class" string inserts a single character, the function implementation of inserting a string

#include <iostream> #include <stdlib.h> #include <assert.h>using namespace std;class  string{public:    string (CONST&NBSP;CHAR*&NBSP;STR)       &NBSP;&NBSP;&NBSP;:_STR (New char[strlen (str)  + 1])     {         _size = strlen (str);         _ capacity = _size + 1;        strcpy (_str, str );       }        string (const  String& s)         :_str (NULL)     {         string tmp (S._STR);         swap (_STR,&NBSP;TMP._STR);     }    ~string ()      {        if  (_STR)         {             delete[] _str;             _size =0;             _capacity =0;            _str  = NULL;        }    }         //inserts a single character     void insert (char ch, size_t  POS)     {        assert (pos <= _size) ;         checkcapacility ();         size_t begin = _size;        while  (begin  >= pos)         {             _str[begin + 1] = _str[begin];             begin--;        }         _str[pos] = ch;        ++_size;     }        //Insert String     /*void  insert (SIZE_T&NBSP;POS,&NBSP;CONST&NBSP;CHAR*&NBSP;S1)     {                             assert (pos <= _size);                 int len = strlen (S1);         cHeckcapacility (_size+len+1);         size_t begin = _ size;        while  (Begin >= pos)          {            _str[ begin + len] = _str[begin];             --begin;        }         for  (int i = 0; i < len;i++)          {            _str[pos++] =  s1[i];        }    }     Char* cstr ()     {        return _str;     }privaTe:    void checkcapacility (Int needlen)     {                 if  (needlen > = _capacity)         {             _capacity = needlen > 2 * _capacity ?  Needlen : 2 * _capacity;             _str =  (char*) realloc (_str, _capacity);         }    }private:    char* _str;    int  _size;    int _capacity;}; Void test () {    string s ("helorld,hello bit!");     s.insert (3, "lo w");     cout << s.cstr () &nBsp;<< endl;} Int main () {    test ();     system ("Pause");     return 0;}

C + + "String class" string inserts a single character, the function implementation of inserting a string