C++编程基础——字符串类设计与实现实战

头文件：

#ifndef _MYSTRING_H_
#define _MYSTRING_H_

#include 

namespace dj
{
    class mystring
    {
    private:
        char* buff;

    public:
        mystring();
        mystring(const char* str);
        mystring(const mystring& str);
        virtual ~mystring();

        int size() const;
        bool empty() const;
        const char* c_str() const;

        void append(char c);
        void append(const char* str);
        void append(int i);
        void insert(unsigned int pos, char c);
        void insert(unsigned int pos, const char* str);
        bool remove(char c);
        bool remove(const char* str);
        bool update(char old_c, char new_c);
        int find(char c);
        int find(const char* str);

        mystring& operator=(const mystring& str);
        bool operator==(const mystring& str);
        mystring operator+(const mystring& str); 
        char& operator[](int i);

        friend std::ostream& operator<<(std::ostream& out, const mystring& s);
        friend std::istream& operator>>(std::istream& in, mystring& s);
    };
}


#endif

源文件：

#include 
#include 
#include 
#include "mystring.h"

namespace dj
{

mystring::mystring()
{
    this->buff = new char{'}';}
::

mystringmystring(constchar *) str=
{
    this->buff char new [strlen()str+ 1 ];strcpy
    (,this->buff) str;}
::

mystringmystring(const& mystring) str=
{
    this->buff char new [strlen(.str)buff+ 1 ];strcpy
    (,this->buff. str)buff;}
::

mystring~mystring()if
{
    (!=this->buff ) nullptr[
        delete]; this->buff}
int

:: mystringsize()const int
{  
    = cnt 0 ;while
    ([this->buff]cnt!= ')' ++; returncnt;
    } cnt::
empty

bool mystring()constreturn [
{
    0 this->buff]==';' } constchar
*

:: c_str( mystring)constreturn; }
{
    void this->buff::
append

( mystringchar)char* c=
{
    char[ tmp strlen new ()+1this->buff+ 1 ] ; sprintf(,
    "%s%c",tmp, ); this->buff[ c];
    delete=; this->buff}
    this->buff void tmp::
append

( mystringconstchar*) char* str=
{
    char[ tmp strlen new ()+strlenthis->buff( ) +1str] ; sprintf(,
    "%s%s",tmp, ); this->buff[ str];
    delete=; this->buff}
    this->buff void tmp::
append

( mystringint)char[ i15
{
    ] num;sprintf(,
    "%d",num) ;append i()
    this->;}numvoid::
insert

( mystringunsignedint,char ) posif ( cstrlen
{
    ()pos > )=this->buffstrlen( 
        pos ) ;charthis->buff*=

    char[ tmp strlen new ()+1this->buff+ 1 ] ; strncpy(,
    ,)tmp; this->buffsprintf pos(+
    ,"%c%s"tmp , pos, +) c; this->buff [ pos];
    delete=; this->buff}
    this->buff void tmp::
insert

( mystringunsignedint,const char pos* ) if( strstrlen
{
    ()pos > )=this->buffstrlen( 
        pos ) ;charthis->buff*=

    char[ tmp strlen new ()+strlenthis->buff( ) +1str] ; strncpy(,
    ,)tmp; this->buffsprintf pos(+
    ,"%s%s"tmp , pos, +) str; this->buff [ pos];
    delete=; this->buff}
    this->buff :: tmpremove
(

bool mystringchar)int; cfor
{
    ( pos=
    0;pos [ ]!= this->buff'&&'pos[ ] != ; this->buff++pos) ; cif pos([]

    ==')'this->buffreturnpos; do [] = false[

    +
    {
        this->buff1pos] ; this->buff++pos ; }while(
        pos[]
    != ')' ;this->buffreturnpos; } ::remove(
    
    const truechar
*

bool mystring)char*= strstr( str,
{
    ); p if (==this->buff) strreturn;

    int=nullptr - p; int false=

    strlen pos ( p ) this->buff;
    do len [ ]=str[+

    ]
    {
        this->buff;pos++ ; this->buff}pos while len([
        pos]!=
    ')' ; returnthis->buff;pos} :: update(char
    
    , truechar
)

bool mystringint;for( old_c= 0 new_c;
{
    [ pos]
    !='&&'pos [ ]!= this->buff;pos++ ) ; if this->buff(pos[ ] old_c== pos')'return;

    []this->buff=pos; return ;} int false:: 

    this->bufffindpos( char new_c)

    int true;   
for

( mystring=0;[ c]
{
    != pos';'
    ++)pos if ([ this->buff]pos== ) return; pos}return
    {
        -1this->buff;pos} int c:: find pos(
    const

    char *)char
*

= mystringstrstr(,) ;if str(
{
    ==) p return -1this->buff; strreturn-
    ;}nullptr & p:: = (const&
    ) p [ this->buff]
;

mystring= mystringcharoperator[strlen( mystring. str)
{
    delete+1 this->buff]
    this->buff ; new strcpy(,.str)buff; return *;}
    ::==this->buff( strconstbuff&)  

    return !thisstrcmp
(

bool mystring,operator.); mystring} str::
{
    + (const&this->buff) str;buff.append
(

mystring mystring)operator;.append mystring( str.
{
    mystring tmp)
    tmp;return;this->buff}char
    tmp&::[str]buff(int
    ) tmpreturn
[

]; mystring}operator::&<<( i::
{
    & this->buff,iconst&
)

std<<ostream. operator;returnstd;ostream} out:: & mystring( s::
{
    out & s,buff&
    ) outchar
[

std1025istream] operator>>;std.istreamgetline in( mystring, ssizeof
{
    ( tmp));[
    in].;tmp. =chartmp[strlen(

    delete)+ s1buff]
    s;buff strcpy new (.,)tmp; return ;}}
    #includes#buffinclude tmp"mystring.h"#    

    include in;
int

main

调用文件：

() 
// mystring s1;// mystring s2("abcd"); // mystring s3 = "123";
// s1 = "hello";// cout << s1.size() << endl; 
using namespace std// cout << s2.size() << endl;


// cout << s3.size() << endl; // s3 = "";// if(s3.empty())//     cout << "s3 is empty!" << endl;
{
    // }
    // s1.append(',');
    // s1.append("world");

    // s1.append(123);

    // s1.insert(0, "haha ");
    // s1.insert(5, "你好 ");
    // s1.remove(' ');

    // s1.remove("123");

    // if(!s1.remove("432"))
    // {
    //     cout << "删除失败！" << endl;
    // }

    // cout << s1 << endl;
    // while(s1.update('a', 'b'));
    // cout << s1 << endl;
    // mystring userName;
    // cout << "用户名：";
    // if(userName == "zhangsan")
    //     cout << "用户名正确！" << endl;

    // }
    // {
    // printf("%s\n", userName.c_str());
    // s1 = s2 + s3 + "abc";

    // s1 = mystring("abc") + "def";

    // cout << s1 << endl;

    // string s = "abcdef";

    // const char* p = s.c_str();

    // for(int i = 0; i < s.size(); i++)
    // cin >> userName;

    //     cout << s[i] << endl;
    // {
    // s[2] = 'm'; 
    // cout << s << endl;   

    ;

    =

    "fdsafdlfldasfkljdsafkljdsafkljdsafkljdsafd;asfdasf"

    ;

    <<

    sizeof

    (
    )

    <<

    ;

    using namespace dj<<
    
    mystring s . size(

    cout ) <<;sreturn 0 endl;
    cout } s  endl