C++学习之路（六）：实现一个String类

直接贴代码吧，这段时间准备面试也正好练习了一下。

class String
{
public:
    String(const char *str = "");
    ~String(void);
    String(const String &other);
    String &operator =(const String &other);
    size_t size(void) const;
    const char *c_str(void);
    
private:
    char *m_str;
};

String::String(const char *str)
{
    int len = strlen(str);
    m_str = new char[len + 1];
    strcpy(m_str, str);
}

String::~String(void)
{
    delete []m_str;
}

String::String(const String &other)
{
    int len = strlen(other.m_str);
    m_str = new char[len + 1];
    strcpy(m_str, other.m_str);
}

String& String::operator=(const String &other)
{
    if (other == *this)
        return *this;
    delete []m_str;
    int len = strlen(other.m_str);
    m_str = new char[len + 1];
    strcpy(m_str, other.m_str);
    return *this;
}

size_t String::size(void)
{
    return strlen(m_str);
}

const char* String::c_str(void)
{
    return m_str;
}