class CMyString
{
public:
    CMyString(char* pData = nullptr);
    CMyString(const CMyString& str);
    ~CMyString(void);

    CMyString& operator = (const CMyString& str);

    void Print();

private:
    char* m_pData;
};

#include <cstdio>
#include <cstring>


class CMyString {

public:
    CMyString(char* pData = nullptr);
    CMyString(const CMyString& str);
    CMyString& operator = (const CMyString& str);
    void Print();
    ~CMyString(void);

private:
    char* m_pData;

};

CMyString::CMyString(char* pData) {
    if(pData == nullptr) {
        m_pData = new char[1];
        m_pData[0] = ‘\0‘;
    } else {
        int len = strlen(pData);
        m_pData = new char[len + 1];
        strcpy(m_pData,pData);
    }
}

CMyString::CMyString(const CMyString& str) {

    int len = strlen(str.m_pData);
    m_pData = new char[len + 1];
    strcpy(m_pData,str.m_pData);

}
//CMyString& CMyString::operator = (const CMyString& str){
//    if(this == &str)
//        return *this;
//
//    delete[] m_pData;
//    m_pData = nullptr;
//
//    m_pData = new char[strlen(str.m_pData) + 1];
//    strcpy(m_pData,str.m_pData);
//
//    return *this;
//
//}

CMyString& CMyString::operator = (const CMyString& str) {

    if(this != &str) {

        CMyString strTmp(str);

        char* pTmp = strTmp.m_pData;
        strTmp.m_pData = m_pData;
        m_pData = pTmp;


    }

    return *this;
}

void CMyString::Print() {

    printf("%s", m_pData);

}


CMyString ::~CMyString() {
    delete[] m_pData;

}

//=================TEST==================
void Test1() {

    printf("Test1 begins:\n");

    char* text = "Hello world!";

    CMyString str1(text);
    CMyString str2;
    str2 = str1;

    printf("The expected result is: %s.\n",text);

    printf("The actual result is: ");
    str2.Print();
    printf(".\n");

}

void Test2(){

    printf("Test2 begins:\n");

    char* text = "Hello world!";

    CMyString str1(text);
    str1 = str1;

    printf("The expected result is: %s.\n",text);

    printf("The actual result is: ");
    str1.Print();
    printf(".\n");

}

void Test3(){

    printf("Test3 begins:\n");

    char* text = "Hello world!";

    CMyString str1(text);
    CMyString str2,str3;
    str3 = str2 = str1;

    printf("The expected result is: %s.\n",text);

    printf("The actual result is ");
    str2.Print();
    printf(".\n");

    printf("The actual result is ");
    str3.Print();
    printf(".\n");

}


int main() {
    Test1();
    Test2();
    Test3();


    return 0;
}