自定义String

// ShStringNew.cpp : 定义控制台应用程序的入口点。
//
 
#include "stdafx.h"
#include<iostream>
#include<iomanip>
using namespace std;
class SHString
{
 
public:
    SHString(const char* Str = "")
        :mStr(new char[strlen(Str) + 1])
    {
        strcpy(mStr, Str);
    }
    SHString(const SHString& Str)
        :mStr(new char[strlen(Str.mStr) + 1])
    {
        strcpy(mStr, Str.mStr);
    }
    SHString& operator=(const char* Str)
    {
        delete[] mStr;
        mStr = new char[strlen(Str) + 1];
        strcpy(mStr, Str);
        return *this;
    }
    SHString& operator=(const SHString& Str)
    {
        if (this != &Str)
        {
            delete[]mStr;
            mStr = new char[strlen(Str.mStr) + 1];
            strcpy(mStr, Str.mStr);
        }
        return *this;
    }
    ~SHString()
    {
        delete[]mStr;
        mStr = NULL;
    }
 
 
public:
    char* mStr;
    friend ostream& operator<<(ostream& os, SHString& S);
    friend istream& operator >> (istream&, SHString& S);
    SHString operator+(const SHString &other);  //operator+
 
};
 
//因为模拟实现的string不是内置类型，所以要重载输出运算符，才能输出String类对象的内容
ostream& operator<<(ostream& os, SHString& Str)
{
    os << Str.mStr;
    return os;
}
 
istream &operator >> (istream &input, SHString &s)
{
    char temp[255]; //用于存储输入流
    input >> setw(255) >> temp;
    s = temp; //使用赋值运算符
    return input; //使用return可以支持连续使用>>运算符
}
 
inline SHString SHString::operator+(const SHString &other)
{
    SHString NewString;
 
    NewString.mStr = new char[strlen(mStr) + strlen(other.mStr) + 1];
    strcpy(NewString.mStr, mStr);
    strcat(NewString.mStr, other.mStr);
 
    return NewString;
}
int main()
{
    SHString Str1("abcdef");
    SHString Str2("ABCDEF");
    SHString Str3(Str1);
    SHString Str4,Str5,Str6;
    Str4 = Str1;
    char* v1 = "123";
    Str5 = v1;
    Str6 = Str4 + Str5;
    cout << "Str1->" << Str1 << endl;
    cout << "Str2->" << Str2 << endl;
    cout << "Str3->" << Str3 << endl;
    cout << "Str4->" << Str4 << endl;
    cout << "Str5->" << Str5 << endl;
    cout << "Str6->" << Str6 << endl;
    return 0;
}