MyString.h文件
#define _CRT_SECURE_NO_WARNINGS#pragma once#include<iostream>#include<string>using namespace std;class MyString{friend ostream & operator<<(ostream & cout, MyString & str);friend istream & operator>>(istream &cin, MyString & str);public:MyString(const char *);MyString(const MyString & str);~MyString();//重载等号运算符MyString & operator=(const char *str);MyString & operator=(const MyString & str);//重载[]运算符char & operator[](int index);//重载+运算符MyString operator+( char *str);MyString operator+( MyString & str);//重载 == 运算符bool operator ==(const char * str);bool operator==(const MyString & str);private:char * pString;//执行堆区指针int m_Size; //字符串大小};
MyString.cpp文件
#define _CRT_SECURE_NO_WARNINGS#include"MyString.h"//左移运算符重载ostream & operator<<(ostream & cout, MyString & str){cout << str.pString;return cout;}//右移运算符istream & operator>>(istream &cin, MyString & str){//先判断 原始是否有内容if (str.pString != NULL){delete[]str.pString;str.pString = NULL;}//让用户输入内容char buf[1024];cin >> buf;//把用户输入的字符串 赋值给strstr.pString = new char[strlen(buf) + 1];strcpy(str.pString, buf);str.m_Size = strlen(buf);return cin;}MyString::MyString(const char * str){printf("有参构造调用\n");this->pString = new char[strlen(str) + 1];strcpy(this->pString, str);this->m_Size = strlen(str);}MyString::MyString(const MyString & str){printf("拷贝构造调用\n");this->pString = new char[strlen(str.pString) + 1];strcpy(this->pString, str.pString);this->m_Size = str.m_Size;}MyString::~MyString(){//printf("析构调用\n");if (this->pString != NULL){delete[]this->pString;this->pString = NULL;}}MyString& MyString::operator=(const char *str){if (this->pString != NULL){delete[]this->pString;this->pString = NULL;}this->pString = new char[strlen(str)+1];strcpy(this->pString, str);return *this;}MyString& MyString::operator=(const MyString & str){if (this->pString != NULL){delete[]this->pString;this->pString = NULL;}this->pString = new char[strlen(str.pString) + 1];strcpy(this->pString, str.pString);return *this;}char & MyString::operator[](int index){return this->pString[index];}MyString MyString::operator+(const char * str){//计算返回的字符串开辟的大小int newSize = this->m_Size + strlen(str) + 1;char * tmp = new char[newSize];memset(tmp, 0, newSize);//拼接字符串strcat(tmp, this->pString);strcat(tmp, str);MyString newStr(tmp);delete[]tmp;return newStr;}MyString MyString::operator+(const MyString & str){//计算返回的字符串开辟的大小int newSize = this->m_Size + strlen(str.pString) + 1;char * tmp = new char[newSize];memset(tmp, 0, newSize);//拼接字符串strcat(tmp, this->pString);strcat(tmp, str.pString);MyString newStr(tmp);delete[]tmp;return newStr;}bool MyString:: operator ==(const char * str){if (str == NULL){return false;}if (strcmp(this->pString, str) == 0 && this->m_Size == strlen(str)){return true;}return false;}bool MyString::operator==(const MyString & str){if (&str == NULL){return false;}if (strcmp(this->pString, str.pString) == 0 && this->m_Size == strlen(str.pString)){return true;}return false;}
测试文件
#include"MyString.h" void test01(){MyString str = "abc";cout << str << endl;/*cout << "请输入str新的内容" << endl;cin >> str;cout << "新内容为" << str<<endl;*/MyString str2(str);MyString str3 = "aaaaaaaaa";str3 = str2;str3 = "aaaa";cout << "str3=" << str3 << endl;str3[0] = 'w';cout << "str3第一个位置为" << str3[0] << endl;MyString str4 = " ";//str4 = str2 +str3;//字符串拼接cout << "str4为" << str4 << endl;if (str3 == str4){cout << "str3与str4相等" << endl;}else{cout << "str3与str4不相等" << endl;}}int main(){test01();system("pause");return 0;}
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