C + + String class

Header file "String.h" #include  <iostream> #include  <assert.h>using namespace std;class  string{public:    string (const char* str =  "")      {        int len = strlen (str);         _capacity = len + 1;         _size = len;        _str = new  char[_capacity];        strcpy (_STR,&NBSP;STR);     }    //interchange function     void _swap (string& s)        {        swap (_STR,&NBSP;S._STR);         swap (_size, s._size);         Swap (_capacity, s._capacity);     }    string (const string& s)          :_str (New char[1] ())     {         string tmp = s._str;        _ Swap (TMP);     }    //destructor     ~string ()        {        if  (_STR)          {            delete[ ]_str;            _str = null;         }    }    void display ( )     {        cout << _str  << endl;    }    /********************************************************/     /*********************** Overloading individual operators *******************/    /**************** /        string&  Operator= (string s)     {        string _ Swap (s);        return *this;    }     bool operator> (const string& s)     {   &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;RETURN&NBSP;STRCMP (_STR,&NBSP;S._STR)  > 0 ? true  : false;    }    bool operator< (const string & s)     {        return strcmp (_STR, &NBSP;S._STR) >0 ? false : true;    }    bool operator== (const String & s)     {        return strcmp (_STR, &NBSP;S._STR)  == 0 ? true : false;    }     bool operator>= (const string& s)     {     &NBSP;&NBSP;&NBSP;&NBSP;RETURN&NBSP;STRCMP (_STR,&NBSP;S._STR)  >= 0 ? true :  false;    }    bool operator<= (Const String& s) &NBSP;&NBSP;&NBSP;&NBSP;{&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;RETURN&NBSP;STRCMP (_STR,&NBSP;S._STR)  <= 0 ? true : false;    }    /****** /    /*********************** Implementing string Common Functions ***********/    /************************************************************/     //Tail plug     void pushback (char ch)     {         _checkcapacity (_size + 2);         _str[_size++] = ch;        _str[_size] =   ' + ';     }    //pos position insertion character ch    void  Insert (size_t pos, char ch)     {         assert (pos <= _size);         _checkcapacity (_size &NBSP;+&NBSP;2);        int end = _size + 1;         while  (End >= pos)          {            _str[end] = _str[end -  1];            --end;         }        _str[pos - 1] =  ch;        ++_size;    }     /*    int len = 1;    _size += len;     _str = _checkcapacity ();    for  (size_t i  = _size; i >= pos; i++)     {         _str[i] = _str[i - 1];    }     _str[pos - 1] = ch;    */    //pos Position Inserts a string     void inSERT (SIZE_T&NBSP;POS,&NBSP;CONST&NBSP;CHAR*&NBSP;STR)     {         assert (pos <= _size);         size_t  strsize = strlen (str);         _checkcapacity (_size  + 1 + strsize);         int end = _ size;        while  (end >=  (int) POS)          {            _ str[end + strsize] = _str[end];             --end;        }         while  (*STR)         {             _str[pos++] = *str++;        }         _size += strsize;    }    char & operator[] (Size_t index)     {         return _str[index];    }    //find a character      int find (char ch)     {        for   (size_t i = 0; i < _size; i++)          {            if  (_str[i] == &NBSP;CH)             {                 return i;             }        }         return -1;    }    //find A String      int find (CONST&NBSP;CHAR*&NBSP;STR)     {         const char* pscr = _str;        const  char* psub =  str;        int scrlen  = _size;        int sublen = strlen (str);         int scrIndex = 0;         while  (Scrindex <= scrlen - sublen)          {            int i  = scrindex;            int j = 0;             while  (scrlen > i&&j <  SUBLEN&AMP;&AMP;PSCR[I]&NBSP;==&NBSP;PSUB[J])              {                i ++;                j++;             }             if  (J == sublen)              {                 return scrindex;            }              scrindex++;        }         return -1;    }     //n characters after deleting pos position     void erase (size_t pos, size_t n)      {        assert (pos < _size);         for  (size_t i = pos; i < _size;  i++)         {             _str[i] = _str[i + n];         }        _size -= n;    }     //Delete the pos position character     void erase (Size_t pos)      {&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBsp;  assert (pos < _size);        for  ( size_t i = pos; i < _size; i++)          {            _str[i] = _str[ i + 1];        }         _size--;    }private:    //Check that the pointer is pointing to the size of the space and expanding      void _checkcapacity (size_t size)     {         if  (size >= _capacity)         {             int newCapacity = size  > 2 * _capacity ? size : 2 * _capacity;             _str =  (char*) realloc (_str, newcapacity);             _capacity = newCapacity;         }    }    char *_str;            //string Pointer     size_t _size;         //string Capacity     size_t _capacity;   //string space size };//Test Void test1 () {    string s1 ("Hello world");     s1. Display ();     string s2 (S1);     s2. Display (); &NBSP;&NBSP;&NBSP;&NBSP;STRING&NBSP;S3 ("Change world");    s1 =  S3;    s1. Display ();} Void test2 () {    string s1 ("Ello world");     s1. Insert (1,  ' H');     s1. Display ();} Void test3 () {    string s1 ("Hello rld");    char*  str =  "Wo";     s1. Insert (6,&NBSP;STR);     s1. Display ();} Void test4 () {    string s1 ("Hello");    cout <<  s1[0] << endl;} Void test5 () {    string s1 ("Hello world");     cout  << s1. Find ("ll")  << endl;} Void test6 () {    string s1 ("Hello world");     s1. Erase (2, 3);     s1. Display ();} " Test.cpp "#include  " String.h "Int main () {    test1 ();     test2 ();     test3 ();     test4 ();     test5 ();     test6 ();     system ("PAuse ");     return 0;} 

This article from "Wooden Man" blog, declined reprint!

C + + String class