auto Movie::operator==(const Movie& another) -> bool { if (another.name != this->name && another.name != "*") return false; if (another.director != this->director && another.director != "*") return false; if (another.actor != this->actor && another.actor != "*") return false; if (another.time != this->time && another.time != "*") return false; return true; } 是什么意思
时间: 2024-03-07 19:53:42 浏览: 79
这段代码定义了一个名为 `operator==` 的函数,它是一个 `Movie` 类的成员函数,用于判断两个电影对象是否相等。
该函数接受一个 `const Movie&` 类型的参数 `another`,表示另一个电影对象。
函数内部会依次比较两个电影对象的名称、导演、演员和上映时间,如果它们不相等且 `another` 中对应的属性不是 `*`,则返回 `false`。如果所有属性都相等或者 `another` 中对应的属性是 `*`,则返回 `true`。
这个函数重载了 `==` 运算符,使得两个 `Movie` 类型的对象可以直接使用 `==` 运算符进行比较。比如,`Movie m1, m2; bool result = m1 == m2;` 就是在调用这个函数。
相关问题
#include "movie.h" #include <QString> #include <fstream> using std::string; //创建电影类 Movie::Movie() {} Movie::Movie(string name, string director, string actor, string time) { this->name = name;//电影名称 this->director = director;//导演 this->actor = actor;//演员 this->time = time;//上映时间 } //搜索匹配关键字 auto Movie::isMatched(string name, string director, string actor, string time) -> bool { bool ret = true; if (this->name.find(name) == string::npos) ret = false; if (this->actor.find(actor) == string::npos) ret = false; if (this->director.find(director) == string::npos) ret = false; if (this->time.find(time) == string::npos) ret = false; return ret; } //把电影对象转化成字符串 auto Movie::toString() const -> string { char buffer[1024]; sprintf(buffer, "%30s%30s%30s%30s", this->name.c_str(), this->director.c_str(), this->actor.c_str(), this->time.c_str()); return string(buffer); } //重载输入流运算符,将数据从文件中读取 auto operator>>(std::ifstream& is, Movie& m) -> std::ifstream& { is >> m.name >> m.director >> m.actor >> m.time; return is; } //重载输入流运算符,将数据写入文件中 auto operator<<(std::ofstream& os, const Movie& m) -> std::ofstream& { os << m.toString(); return os; } auto Movie::toQStringList() const -> QStringList { QStringList ret; ret.append(QString::fromStdString(this->name)); ret.append(QString::fromStdString(this->director)); ret.append(QString::fromStdString(this->actor)); ret.append(QString::fromStdString(this->time)); return ret; } auto Movie::operator==(const Movie& another) -> bool { if (another.name != this->name && another.name != "*") return false; if (another.director != this->director && another.director != "*") return false; if (another.actor != this->actor && another.actor != "*") return false; if (another.time != this->time && another.time != "*") return false; return true; } 什么意思
这段代码定义了一个电影类 `Movie`,包含电影名称、导演、演员、上映时间等信息,并提供了一些方法来操作这些信息。
具体来说:
- 构造函数 `Movie::Movie()` 和 `Movie::Movie(string name, string director, string actor, string time)` 用于创建电影对象,可以传入电影名称、导演、演员、上映时间等信息。
- 方法 `Movie::isMatched(string name, string director, string actor, string time)` 用于判断电影对象是否匹配给定的关键字,即电影名称、导演、演员、上映时间是否包含给定的字符串。
- 方法 `Movie::toString() const` 将电影对象转化成字符串。
- 运算符重载 `operator>>` 和 `operator<<` 用于将电影对象从文件中读取和写入文件中。
- 方法 `Movie::toQStringList() const` 将电影对象转化成 `QStringList`,用于在 Qt 的界面中显示电影信息。
- 运算符重载 `operator==` 用于比较两个电影对象是否相等,即电影名称、导演、演员、上映时间是否相等。其中,如果电影名称、导演、演员、上映时间有一个不匹配,则返回 false。如果其中一个属性值为 "*",则表示该属性不进行比较,即忽略该属性。
填充下面这个程序中所有出现// TODO: fill the code这个任务的地方#include <iostream> #include <cstring> #include "ourstring.h" #include "strlib.h" using namespace std; OurString::OurString(){ // TODO: fill the code } OurString::OurString(const char *str){ // TODO: fill the code } OurString::OurString(const OurString &dstr){ // TODO: fill the code } OurString::~OurString(){ // TODO: fill the code } string OurString::toString() const{ // TODO: fill the code } OurString OurString::subStr(unsigned int start, unsigned int n) const{ // TODO: fill the code } bool OurString::operator > (const OurString &dstr) const{ // TODO: fill the code } bool OurString::operator < (const OurString &dstr) const{ // TODO: fill the code } bool OurString::operator == (const OurString &dstr) const{ // TODO: fill the code } unsigned int OurString::length () const{ // TODO: fill the code } const OurString& OurString::operator = (const OurString &dstr){ // TODO: fill the code } const OurString& OurString::operator = (const char *str){ // TODO: fill the code } char& OurString::operator[](int index){ // TODO: fill the code } const OurString OurString::operator + (const OurString &dstr) const{ // TODO: fill the code } const OurString OurString::operator + (const char *str) const{ // TODO: fill the code } const OurString& OurString::operator += (const OurString &dstr){ // TODO: fill the code } const OurString& OurString::operator += (const char *str){ // TODO: fill the code } ostream & operator<<(ostream &os, const OurString &dstr){ // TODO: fill the code } istream & operator>>(istream &is, OurString &dstr){ // TODO: fill the code }
好的,下面是填充后的代码,每个 TODO 已经被替换成相应的实现:
```c++
#include <iostream>
#include <cstring>
#include "ourstring.h"
#include "strlib.h"
using namespace std;
OurString::OurString(){
str = new char[1];
str[0] = '\0';
}
OurString::OurString(const char *str){
this->str = new char[strlen(str)+1];
strcpy(this->str, str);
}
OurString::OurString(const OurString &dstr){
this->str = new char[dstr.length()+1];
strcpy(this->str, dstr.str);
}
OurString::~OurString(){
delete [] str;
}
string OurString::toString() const{
return string(str);
}
OurString OurString::subStr(unsigned int start, unsigned int n) const{
if (start >= length()) return OurString();
n = (n > length() - start) ? length() - start : n;
return OurString(str + start, str + start + n);
}
bool OurString::operator > (const OurString &dstr) const{
return strcmp(str, dstr.str) > 0;
}
bool OurString::operator < (const OurString &dstr) const{
return strcmp(str, dstr.str) < 0;
}
bool OurString::operator == (const OurString &dstr) const{
return strcmp(str, dstr.str) == 0;
}
unsigned int OurString::length () const{
return strlen(str);
}
const OurString& OurString::operator = (const OurString &dstr){
if (this != &dstr) {
delete [] str;
str = new char[dstr.length()+1];
strcpy(str, dstr.str);
}
return *this;
}
const OurString& OurString::operator = (const char *str){
if (this->str != str) {
delete [] this->str;
this->str = new char[strlen(str)+1];
strcpy(this->str, str);
}
return *this;
}
char& OurString::operator[](int index){
return str[index];
}
const OurString OurString::operator + (const OurString &dstr) const{
OurString s;
s.str = new char[length() + dstr.length() + 1];
strcpy(s.str, str);
strcat(s.str, dstr.str);
return s;
}
const OurString OurString::operator + (const char *str) const{
OurString s;
s.str = new char[length() + strlen(str) + 1];
strcpy(s.str, this->str);
strcat(s.str, str);
return s;
}
const OurString& OurString::operator += (const OurString &dstr){
*this = *this + dstr;
return *this;
}
const OurString& OurString::operator += (const char *str){
*this = *this + str;
return *this;
}
ostream & operator<<(ostream &os, const OurString &dstr){
os << dstr.str;
return os;
}
istream & operator>>(istream &is, OurString &dstr){
string s;
is >> s;
dstr = s.c_str();
return is;
}
```
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