MyString.cpp

#include "MyString.h"
#include <cstring>
#include <stdexcept>

int MyString::stringLength(const char* s) const
{
    int len = 0;

    while (s[len] != '\0')
        len++;

    return len;
}

void MyString::copyString(char* dest, const char* src) const
{
    int i = 0;

    while (src[i] != '\0')
    {
        dest[i] = src[i];
        i++;
    }

    dest[i] = '\0';
}

int MyString::compareString(const char* s1, const char* s2) const
{
    int i = 0;

    while (s1[i] != '\0' && s2[i] != '\0')
    {
        if (s1[i] != s2[i])
            return s1[i] - s2[i];

        i++;
    }

    return s1[i] - s2[i];
}

MyString::MyString()
{
    length = 0;
    str = new char[1];
    str[0] = '\0';
}

MyString::MyString(const char* s)
{
    length = stringLength(s);

    str = new char[length + 1];

    copyString(str, s);
}

MyString::MyString(const MyString& other)
{
    length = other.length;

    str = new char[length + 1];

    copyString(str, other.str);
}

MyString::~MyString()
{
    delete[] str;
}

MyString& MyString::operator=(const MyString& other)
{
    if (this != &other)
    {
        delete[] str;

        length = other.length;

        str = new char[length + 1];

        copyString(str, other.str);
    }

    return *this;
}

MyString MyString::operator+(const MyString& other) const
{
    MyString temp;

    delete[] temp.str;

    temp.length = length + other.length;

    temp.str = new char[temp.length + 1];

    int i;

    for (i = 0; i < length; i++)
        temp.str[i] = str[i];

    for (int j = 0; j < other.length; j++)
        temp.str[i++] = other.str[j];

    temp.str[i] = '\0';

    return temp;
}

bool MyString::operator==(const MyString& other) const
{
    return compareString(str, other.str) == 0;
}

bool MyString::operator!=(const MyString& other) const
{
    return !(*this == other);
}

char& MyString::operator[](int index)
{
    if (index < 0 || index >= length)
        throw out_of_range("Index out of range");

    return str[index];
}

const char& MyString::operator[](int index) const
{
    if (index < 0 || index >= length)
        throw out_of_range("Index out of range");

    return str[index];
}

int MyString::size() const
{
    return length;
}

bool MyString::empty() const
{
    return length == 0;
}

void MyString::clear()
{
    delete[] str;

    length = 0;

    str = new char[1];

    str[0] = '\0';
}

const char* MyString::c_str() const
{
    return str;
}

ostream& operator<<(ostream& out, const MyString& s)
{
    out << s.str;

    return out;
}

istream& operator>>(istream& in, MyString& s)
{
    char buffer[1000];

    in >> buffer;

    delete[] s.str;

    s.length = s.stringLength(buffer);

    s.str = new char[s.length + 1];

    s.copyString(s.str, buffer);

    return in;
}