C++ day1

#include <iostream>
#include <cstring>
using namespace std;// 自定义字符串结构体
struct MyString {char* data;size_t length;// 构造函数MyString() {data = nullptr;length = 0;}// 带参数的构造函数MyString(const char* str) {length = strlen(str);data = new char[length + 1];strcpy(data, str);}
};// 获取字符串首地址
char* getAddress(MyString& str) {return str.data;
}// 字符串连接操作
MyString operator+(const MyString& str1, const MyString& str2) {MyString result;result.length = str1.length + str2.length;result.data = new char[result.length + 1];strcpy(result.data, str1.data);strcat(result.data, str2.data);return result;
}// 比较运算符
bool operator>(const MyString& str1, const MyString& str2) {return strcmp(str1.data, str2.data) > 0;
}bool operator==(const MyString& str1, const MyString& str2) {return strcmp(str1.data, str2.data) == 0;
}// 清空字符串
void clear(MyString& str) {delete[] str.data;str.data = nullptr;str.length = 0;
}int main()
{// 测试代码MyString s1("Hello");MyString s2(" World");// 测试加法运算符MyString s3 = s1 + s2;cout << "s3 = " << s3.data << endl;// 测试比较运算符cout << "s1 > s2: " << (s1 > s2) << endl;cout << "s1 == s2: " << (s1 == s2) << endl;// 测试获取首地址cout << "s1的首地址: " << static_cast<void*>(getAddress(s1)) << endl;// 测试清空功能clear(s3);cout << "清空后s3的长度: " << s3.length << endl;return 0;
}