simulate std string

w(ﾟДﾟ)w
C++就没有短的代码
改到哭

Description:
Implement the class String with given header, you can also make it like std::string!

member function ‘compare()’ returns -1 for <, 0 for ==, 1 for >.

Any question see STL references.

more imformation just see the test.

String.h:

#ifndef SSCPP2014_STRING_H#define SSCPP2014_STRING_H#include <iostream>class String {  private:    char *_buff;    int _length, _size;  // _size is of the allocated memory  public:    // constructors    String();    explicit String(const char *src);    String(const String &src);    // destructor    ~String();    // member methods    void assign(const char *src);    void append(const char &other);    void clear();    int compare(const String &other) const;    const char* c_str() const;    bool empty() const;    int find(const String &other, int pos = 0) const;    int length() const;    String substr(const int &pos, const int &count) const;    // overload operators    char& operator[](const int &index);    void operator=(const String &other);    void operator=(const char *src);    String operator+(const String &other) const;    bool operator<(const String &other) const;    bool operator<=(const String &other) const;    bool operator>(const String &other) const;    bool operator>=(const String &other) const;    bool operator==(const String &other) const;    bool operator!=(const String &other) const;    // friend methods    friend std::ostream& operator<<(std::ostream& out, const String &str);    // non-meaning static property    static char _error_sign;  // initial as any char is okay};#endif

String.cpp

#include "String.h"#include<iostream>#include<cstring>using namespace std;String::String() {    _buff = NULL;    _length = _size = 0;}String::String(const char *src) {    _size = strlen(src) + 1;    _buff = new char[_size];    memset(_buff, 0, _size);    snprintf(_buff, _size, "%s", src);    _length = strlen(_buff);}String::String(const String &src) {    _size = src._size;    _length = src._length;    _buff = new char[_size];    memset(_buff, 0, _size);    snprintf(_buff, _size, "%s", src._buff);}String::~String() {    delete [] _buff;}void String::assign(const char *src) {    this->clear();    _size = strlen(src) + 1;    _buff = new char[_size];    memset(_buff, 0, _size);    snprintf(_buff, _size, "%s", src);    _length = strlen(_buff);}void String::append(const char &other) {    if (this->empty()) {        this->assign("o");        _buff[0] = other;    } else {        if (_length + 1 < _size) {            _buff[_length] = other;            _length++;        } else {            _size = _size * 2;            char* o_buff = new char[_size];            memset(o_buff, 0, _size);            snprintf(o_buff, _size, "%s", _buff);            delete[] _buff;            _buff = o_buff;            _buff[_length] = other;            _length++;        }    }}void String::clear() {    if (_buff) {        delete [] _buff;        _buff = NULL;    }    _length = _size = 0;}int String::compare(const String &other) const {    int min = _length < other._length ? _length : other._length;    for (int i = 0; i < min; i++) {        if (_buff[i] < other._buff[i]) {            return -1;        } else if (_buff[i] > other._buff[i]) {            return 1;        }    }    if (_length < other._length) {        return -1;    } else if (_length > other._length) {        return 1;    } else {        return 0;    }}const char* String::c_str() const {    return _buff;}bool String::empty() const {    if (_length == 0) {        return true;    } else {        return false;    }}int String::find(const String &other, int pos) const {    if (other.empty()) return -1;    int count = 0;    for (int i = 0; i < _length; i++) {        if (_buff[i] == other._buff[0]) {            for (int j = 0; j < other._length; j++) {                if (_buff[i + j] == other._buff[pos + j]) count++;            }            if (count == other._length) return i;            count = 0;  //  因为漏了这个改了5、6次/(ㄒoㄒ)/~~        }    }    return _length;}int String::length() const {    return _length;}String String::substr(const int &pos, const int &count) const {    String temp;    if (pos >= _length || pos + count > _length) return temp;    temp._size = count + 1;    temp._buff = new char[temp._size];    memset(temp._buff, 0, temp._size);    snprintf(temp._buff, temp._size, "%s", _buff + pos);    temp._length = strlen(temp._buff);    return temp;}char& String::operator[](const int &index) {    if (index >= 0 && index < _length) {        return _buff[index];    } else {        return _error_sign;    }}void String::operator=(const String &other) {    this->assign(other._buff);}void String::operator=(const char *src) {    this->assign(src);}String String::operator+(const String &other) const {    String temp;    temp._size = this->_length + other._length + 1;    temp._buff = new char[temp._size];    snprintf(temp._buff, _size, "%s", _buff);    snprintf(temp._buff + _length, other._size, "%s", other._buff);    temp._length = strlen(_buff);    return temp;}bool String::operator<(const String &other) const {    return this->compare(other) == -1 ? true : false;}bool String::operator<=(const String &other) const {    return this->compare(other) == 1 ? false : true;}bool String::operator>(const String &other) const {    return this->compare(other) == 1 ? true : false;}bool String::operator>=(const String &other) const {    return this->compare(other) == -1 ? false : true;}bool String::operator==(const String &other) const {    return this->compare(other) == 0 ? true : false;}bool String::operator!=(const String &other) const {    return this->compare(other) == 0 ? false : true;}std::ostream& operator<<(std::ostream& out, const String &str) {    for (int i = 0; i < str._length; i++) {        out << str._buff[i];    }    return out;}char String::_error_sign = '\0';

String Test.cpp

#include <iostream>#include <cstring>#include "String.h"#include <string>using namespace std;String a, b("MFGZ!");String c = b;void display() {  cout << a.empty() << " " << a.length() << " " << a << endl;  cout << b.empty() << " " << b.length() << " " << b << endl;  cout << c.empty() << " " << c.length() << " " << c << endl;}int main() {  string aa, bb, cc;  display();  c[0] = 'K';  display();  cin >> aa >> cc;  a.assign(aa.c_str());  c.assign(cc.c_str());  display();  b.clear();  display();  for (int i = 0 ; i < 10; ++i) {      char t;      cin >> t;      a.append(t);      b.append(t);      c.append(t);  }  display();  b = c;  display();  b = a + c;  display();  cout << a.find(String("1993")) << endl;  cout << b.find(String("HYOUKA")) << endl;  cout << c.find(String("RIKKA")) << endl;  cout << a.substr(0, 3) << endl;  cout << b.substr(3, 8) << endl;  cout << c.substr(6, 1) << endl;  cout << (a > b) << (a >= b) << (a < b) << (a <= b) << (a == b) << endl;  cout << a.compare(b) << b.compare(a) << endl;  cout << (a > c) << (a >= c) << (a < c) << (a <= c) << (a == c) << endl;  cout << a.compare(c) << c.compare(a) << endl;  b = a;  cout << (a > b) << (a >= b) << (a < b) << (a <= b) << (a == b) << endl;  cout << a.compare(b) << b.compare(a) << endl;  cout << a.compare(a) << endl;  return 0;}