Implementation of 2:string class based on algorithm and data structure

Say less nonsense, reject the prelude, direct orgasm, and look at the code:

String.h

#include <iostream> #include <cstring> #pragma warning (disable:4996) using namespace Std;class string{ public://**************************************************************************//class four functions: constructors, copy constructors, Overloaded assignment operator, destructor//**************************************************************************string (const char* str = NULL); String (const string &str); string& operator= (const String &AMP;STR); ~string ();//******************************************************** Heavy Duty//**************************************************************************string operator+ (const String &str) const; string& operator+= (const string &str), bool operator== (const string &str);char& operator[] (unsigned int index); friend ostream& operator<< (ostream& os, string& str); friend istream& Operator>> ( istream& is, string& str), unsigned short size (), const char* C_STR () const;private:private:char* m_string;};/ / ***********Four functions of a class: constructor, copy constructor, overloaded assignment operator, destructor//************ string::string (const char* str) {if (!str) {m_string = NULL;} else{m_string = new Char[strlen (str) + 1];strcpy (m_string, str);}} string::string (const String &AMP;STR) {if (!str.m_string) {m_string = NULL;} else{m_string = new Char[strlen (str.m_string) + 1];strcpy (m_string, str.m_string);}} string& string::operator= (const String &AMP;STR) {if (This! = &str) {delete[] m_string;if (!str.m_string) {m_ string = NULL;} else{m_string = new Char[strlen (str.m_string) + 1];strcpy (m_string, str.m_string);}} return *this;} String::~string () {delete[] m_string;m_string = NULL;} //heavy-duty//***************************** String string::operator+ (const string &str) const{string newstring ; if (!str.m_string) {NewSTring = *this;} else if (!m_string) {newstring = str;} else{newstring.m_string = new Char[strlen (m_string) + strlen (str.m_string) + 1];strcpy (newstring.m_string, m_string); strcat (newstring.m_string, str.m_string);} return newstring;} string& string::operator+= (const string &str) {String newstring;if (!str.m_string) {newstring = *this;} else if (!m_string) {newstring = str;} else{newstring.m_string = new Char[strlen (m_string) + strlen (m_string) + 1];strcpy (newstring.m_string, m_string); strcat (newstring.m_string, str.m_string);} strcpy (m_string, newstring.m_string); return *this;} BOOL string::operator== (const String &AMP;STR) {if (strlen (m_string)! = strlen (str.m_string)) {return false;} Return strcmp (m_string, str.m_string)? False:true;} char& string::operator[] (unsigned int index) {if (Index >=0 && index <=strlen (m_string)) {return m_ String[index];} Else{cout << "Invalid index:" << index << endl;exit (0);} ostream& operator<< (ostream& OS, string&Amp STR) {OS << str.m_string;return os;} istream& operator>> (istream& is, string& str) {char tmp[1024];is >> tmp;str.m_string = new char[ STRLEN (TMP) + 1];strcpy (str.m_string, TMP); return is;} unsigned short string::size () {return strlen (m_string);} Const char* STRING::C_STR () Const{return m_string;}

Main.cpp

#include "String.h" #include <cstdlib>int main () {String s;cin >> s;cout << s << ":" << s.size () << Endl;char a[] = "Hello", b[] = "World"; String S1 (a), S2 (b), cout << S1 << "+" << s2 << "=" << S1 + s2 << Endl; String s3 = S1 + s2;if (S1 = = S3) {cout << "first:s1 = S3" << Endl;} S1 + = s2;if (S1 = = S3) {cout << "second:s1 = = s3" << Endl;} System ("pause"); return 0;}

Output Result:

Report:

strcpy error in vs2013, solution reference:

http://blog.csdn.net/u010273652/article/details/21320431

Implementation of 2:string class based on algorithm and data structure