做网站没资源,装修大全,百度下载文章转wordpress,导航网站前端模板上回我们完成了string类的模拟实现#xff0c;不过之前写的传统写法本篇#xff0c;我们将要对其进行一些改进#xff0c;写成参考的是现代写法#xff0c;这样写可以提高可读性。
上回我们写好的string类
//string.h
#pragma once#define _CRT_SECURE_NO_WARNINGS 1
#p…上回我们完成了string类的模拟实现不过之前写的传统写法本篇我们将要对其进行一些改进写成参考的是现代写法这样写可以提高可读性。
上回我们写好的string类
//string.h
#pragma once#define _CRT_SECURE_NO_WARNINGS 1
#pragma once
#includeiostream
#includeassert.h
using namespace std;namespace STring
{class string{public:typedef char* iterator;typedef const char* const_iterator;iterator begin();iterator end();const_iterator begin() const;const_iterator end() const;//string();string(const char* str );string(const string s);string operator(const string s);~string();const char* c_str() const;size_t size() const;char operator[](size_t pos);const char operator[](size_t pos) const;void reserve(size_t n);void push_back(char ch);void append(const char* str);string operator(char ch);string operator(const char *str);void insert(size_t pos, char ch);void insert(size_t pos, const char* str);void erase(size_t pos 0, size_t len npos);size_t find(char ch, size_t pos 0);size_t find(const char* str, size_t pos 0);void swap(string s);string substr(size_t pos 0, size_t len npos);bool operator(const string s) const;bool operator(const string s) const;bool operator(const string s) const;bool operator(const string s) const;bool operator(const string s) const;bool operator!(const string s) const;void clear();private:// char _buff[16];char* _str;size_t _size;size_t _capacity;// //const static size_t npos -1;// ֧//const static double N 2.2;const static size_t npos;};istream operator (istream is, string str);ostream operator (ostream os, const string str);
}
//string.cpp
#includestring.h
namespace STring
{const size_t string::npos -1;string::iterator string::begin(){return _str;}string::const_iterator string::begin() const{return _str;}string::iterator string::end(){return _str _size;}string::const_iterator string::end() const{return _str_size;}string:: string(const char* str):_size(strlen(str)){_str new char[_size1];_capacity _size1;strcpy(_str, str);}string::string(const string s){_str new char[s._capacity];strcpy(_str, s._str);_size s._size;_capacity s._capacity;}string::~string(){delete[] _str;_str nullptr;_size _capacity 0;}const char* string::c_str() const{return _str;}size_t string :: size() const{return _size;}void string::reserve(size_t n){if (n _capacity){char* tmp new char[n 1];strcpy(tmp, _str);delete[] _str;_str tmp;_capacity n;}}void string::push_back(char ch){if (_size _capacity){size_t newcapacity _capacity 0 ? 4 : _capacity * 2;reserve(newcapacity);}_str[_size] ch;_str[_size 1] \0;_size;}void string::append(const char* str){size_t len strlen(str);if (_size len _capacity){reserve(_size len);}strcpy(_str _size, _str);_size len;insert(_size, _str);}void string::insert(size_t pos, char ch){assert(pos _size);if (_size _capacity){size_t newcapacity _capacity 0 ? 4 : _capacity * 2;reserve(newcapacity);}size_t end _size 1;while (end pos){_str[end] _str[end - 1] 1;--end;}_str[pos] ch;_size;}void string::insert(size_t pos, const char* str){assert(pos _size);int len strlen(str);if (_size len _capacity){reserve(_capacitylen);}size_t end _size len;while (end poslen1){_str[end] _str[end - len];--end;}memcpy(_strpos,str,len);_size len;}void string::erase(size_t pos, size_t len){assert(pos _size);if (len _size - pos){_str[pos] \0;_size len;}else{strcpy(_str pos, _str pos len);_size len;}}size_t string::find(char ch, size_t pos){for (size_t i pos; i _size; i){if (_str[i] ch){return i;}}return npos;}size_t string::find(const char* str, size_t pos){char* p strstr(_str pos, str);return p - _str;}void string::swap(string s){std::swap(_str, s._str);std::swap(_size, s._size);std::swap(_capacity, s._capacity);}string string::substr(size_t pos, size_t len){if (len _size - pos){string sub(_str pos);return sub;}else{string sub;sub.reserve(len);for (size_t i 0; i len; i){sub _str[i pos];}return sub;}}string string:: operator(const string s){if (this ! s){char* tmp new char[s._capacity];strcpy(tmp, s._str);delete[] _str;_str tmp;_size s._size;_capacity s._capacity;}return *this;}char string::operator[](size_t pos){if (pos _size)return _str[pos];}const char string::operator[](size_t pos) const{if (pos _size)return _str[pos];}string string::operator(char ch){push_back(ch);return *this;}string string::operator(const char* str){append(str);return *this;}bool string::operator(const string s) const{return strcmp(_str, s._str) 0;}bool string::operator(const string s) const{return !(*this s);}bool string::operator(const string s) const{return *this s || *this s;}bool string::operator(const string s) const{return !(*this s);}bool string::operator(const string s) const{return strcmp(_str, s._str) 0;}bool string::operator!(const string s) const{return !(*this s);}void string::clear(){_str[0] \0;_size 0;}istream operator (istream is, string str){str.clear();char ch is.get();while (ch ! ch ! \n){str ch;ch is.get();}return is;}ostream operator (ostream os, const string str){for (size_t i 0; i str.size(); i){os str[i];}return os;}
}
以下是现代写法对于 传统写法的改进
一、push_back
传统写法
void string::push_back(char ch)
{if (_size _capacity){size_t newcapacity _capacity 0 ? 4 : _capacity * 2;reserve(newcapacity);}_str[_size] ch;_str[_size 1] \0;_size;
}
现代写法 void string::push_back(char ch){insert(_size, ch);} 二、append
传统写法 void string::append(const char* str){size_t len strlen(str);if (_size len _capacity){reserve(_size len);}strcpy(_str _size, _str);_size len;insert(_size, _str);}
现代写法 void string::append(const char* str){insert(_size, str);}
