重温String类实现
面试时经常会被问到的，请自己实现以下String类。考的很基础的知识，还有考虑问题是否全面。class String{ friend ostream& operator<< (ostream&,String&);public: String(const char* str=NULL); //...........(char) String(const String &other); //......(String) String& operator=(const String&other); //operator= String operator+(const String &other)const; //operator+ bool operator==(const String&); //operator== char& operator[](unsigned int); //operator[] size_t size(){return strlen(m_data);}; ~String(void) {delete[] m_data;}private: char *m_data;};inline String::String(const char* str){ if (!str) m_data=0; else { m_data = new char; strcpy(m_data,str); }}inline String::String(const String& other){ if(!other.m_data) m_data=0; else { m_data=new char; strcpy(m_data,other.m_data); }}inline String& String::operator=(const String& other){ if (this!=&other) { delete[] m_data; if(!other.m_data) m_data=0; else { m_data = new char; strcpy(m_data,other.m_data); } } return *this;}inline String String::operator+(const String &other)const{ String newString; if(!other.m_data) newString = *this; else if(!m_data) newString = other; else { newString.m_data = new char; strcpy(newString.m_data,m_data); strcat(newString.m_data,other.m_data); } return newString;}inline bool String::operator==(const String &s){ if ( strlen(s.m_data) != strlen(m_data) ) return false; return strcmp(m_data,s.m_data)?false:true;}inline char& String::operator[](unsigned int e){ if (e>=0&&e<=strlen(m_data)) return m_data;}ostream& operator<<(ostream& os,String& str){ os << str.m_data; return os;}void main(){ String str1="Hello!"; String str2="Teacher!"; String str3 = str1+str2; cout<<str3<<"\n"<<str3.size()<<endl;}
页:
[1]