重载运算符 *笔记7
普通类型 => 类类型
调用对应的只有一个参数【参数的类型就是这个普通类型】的构造函数
需求：
Boy boy1 = 10000; // 薪资 构造函数Boy(int);
Boy boy2 = "Rock" // 姓名 构造函数Boy(char *);
Boy.h
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#pragma once #include <string> #include <iostream>
#define AGE_KEY "age" #define SALARY_KEY "salary" #define DARK_HORSE_KEY "darkHorse" #define POWER_KEY "power"
typedef enum { AGE, SALARY, DARK_HORSE, POWER }BOY_KEY_TYPE;
using namespace std;
class Boy { public: //Boy(const char* name = NULL, int age = 0, int salary = 0, int darkHorse = 0); Boy(const char* name, int age, int salary, int darkHorse); ~Boy();
Boy(int salary); Boy(const char* name);
Boy& operator=(const Boy& boy);
bool operator>(const Boy& boy); bool operator<(const Boy& boy); bool operator==(const Boy& boy);
// 下标运算符的重载 int operator[](std::string index); int operator[](int index);
// 该方式不适合 //ostream& operator<<(ostream& os) const;
friend ostream& operator<<(ostream& os, const Boy& boy); friend istream& operator>>(istream& is, Boy& boy);
std::string description(void); private: char* name; int age; int salary; int darkHorse; //黑马值，潜力系数 unsigned int id; // 编号 static int LAST_ID;
int power() const; //综合能力值 }; |
Boy.cpp
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#include "boy.h" #include <string.h> #include <sstream>
int Boy::LAST_ID = 0; //初始值是0
Boy::Boy(const char* name, int age, int salary, int darkHorse) { if (!name) { name = "未命名"; }
this->name = new char[strlen(name) + 1]; strcpy_s(this->name, strlen(name) + 1, name);
this->age = age; this->salary = salary; this->darkHorse = darkHorse; this->id = ++LAST_ID; }
Boy::~Boy() { if (name) { delete name; } }
Boy::Boy(int salary) { const char *defaultName = "未命名"; name = new char[strlen(defaultName) + 1]; strcpy_s(name, strlen(defaultName) + 1, defaultName);
age = 0; this->salary = salary; darkHorse = 0; this->id = ++LAST_ID; }
Boy::Boy(const char* name) { this->name = new char[strlen(name) + 1]; strcpy_s(this->name, strlen(name) + 1, name);
age = 0; this->salary = 0; darkHorse = 0; this->id = ++LAST_ID; }
Boy& Boy::operator=(const Boy& boy) { if (name) { delete name; //释放原来的内存 } name = new char[strlen(boy.name) + 1]; //分配新的内存 strcpy_s(name, strlen(boy.name) + 1, boy.name);
this->age = boy.age; this->salary = boy.salary; this->darkHorse = boy.darkHorse; //this->id = boy.id; //根据需求来确定是否要拷贝id return *this; }
bool Boy::operator>(const Boy& boy) { // 设置比较规则： // 薪资 * 黑马系数 + (100-年龄）*100 if (power() > boy.power()) { return true; } else { return false; } }
bool Boy::operator<(const Boy& boy) { if (power() < boy.power()) { return true; } else { return false; } }
bool Boy::operator==(const Boy& boy) { if (power() == boy.power()) { return true; } else { return false; } }
int Boy::operator[](std::string index) { if (index == AGE_KEY) { return age; } else if (index == SALARY_KEY) { return salary; } else if (index == DARK_HORSE_KEY) { return darkHorse; } else if (index == POWER_KEY) { return power(); } else { return -1; } }
int Boy::operator[](int index) { if (index == 0) { return age; } else if (index == 1) { return salary; } else if (index == 2) { return darkHorse; } else if (index == 3) { return power(); } else { return -1; } }
std::string Boy::description(void) { std::stringstream ret; ret << "ID:" << id << "\t姓名:" << name << "\t年龄:" << age << "\t薪资:" << salary << "\t黑马系数:" << darkHorse; return ret.str(); }
int Boy::power() const { // 薪资* 黑马系数 + (100 - 年龄） * 1000 int value = salary * darkHorse + (100 - age) * 100; return value; } |
main.cpp
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#include <iostream> #include "Boy.h"
using namespace std;
ostream& operator<<(ostream& os, const Boy& boy) { os << "ID:" << boy.id << "\t姓名:" << boy.name << "\t年龄:" << boy.age << "\t薪资:" << boy.salary << "\t黑马系数:" << boy.darkHorse; return os; }
istream& operator>>(istream& is, Boy& boy) { string name2; is >> name2 >> boy.age >> boy.salary >> boy.darkHorse; boy.name = (char*)malloc((name2.length() + 1) * sizeof(char)); strcpy_s(boy.name, name2.length() + 1, name2.c_str()); return is; }
int main() { Boy boy1 = 10000; Boy boy2 = "Rock";
cout << boy1 << endl; cout << boy2 << endl;
boy1 = 20000; //boy1 = Boy(20000); cout << boy1 << endl;
return 0; } |
类类型 => 普通类型
调用特殊的运算符重载函数，类型转换函数，不需要写返回类型
类型转换函数：operator 普通类型 ( )
需求：
Boy boy1(“Rock”, 28, 10000, 5);
int power = boy1; // power();
char *name = boy1; // “Rock”
Boy.h
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#pragma once #include <string> #include <iostream>
#define AGE_KEY "age" #define SALARY_KEY "salary" #define DARK_HORSE_KEY "darkHorse" #define POWER_KEY "power"
typedef enum { AGE, SALARY, DARK_HORSE, POWER }BOY_KEY_TYPE;
using namespace std;
class Boy { public: //Boy(const char* name = NULL, int age = 0, int salary = 0, int darkHorse = 0); Boy(const char* name, int age, int salary, int darkHorse); ~Boy();
Boy(int salary); Boy(const char* name);
Boy& operator=(const Boy& boy);
bool operator>(const Boy& boy); bool operator<(const Boy& boy); bool operator==(const Boy& boy);
// 下标运算符的重载 int operator[](std::string index); int operator[](int index);
// 该方式不适合 //ostream& operator<<(ostream& os) const;
friend ostream& operator<<(ostream& os, const Boy& boy); friend istream& operator>>(istream& is, Boy& boy);
// 特殊的运算符重载：类型转换函数，不需要写返回类型 operator int() const; operator char* () const;
std::string description(void); private: char* name; int age; int salary; int darkHorse; //黑马值，潜力系数 unsigned int id; // 编号 static int LAST_ID;
int power() const; //综合能力值 }; |
Boy.cpp
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#include "boy.h" #include <string.h> #include <sstream>
int Boy::LAST_ID = 0; //初始值是0
Boy::Boy(const char* name, int age, int salary, int darkHorse) { if (!name) { name = "未命名"; }
this->name = new char[strlen(name) + 1]; strcpy_s(this->name, strlen(name) + 1, name);
this->age = age; this->salary = salary; this->darkHorse = darkHorse; this->id = ++LAST_ID; }
Boy::~Boy() { if (name) { delete name; } }
Boy::Boy(int salary) { const char *defaultName = "未命名"; name = new char[strlen(defaultName) + 1]; strcpy_s(name, strlen(defaultName) + 1, defaultName);
age = 0; this->salary = salary; darkHorse = 0; this->id = ++LAST_ID; }
Boy::Boy(const char* name) { this->name = new char[strlen(name) + 1]; strcpy_s(this->name, strlen(name) + 1, name);
age = 0; this->salary = 0; darkHorse = 0; this->id = ++LAST_ID; }
Boy& Boy::operator=(const Boy& boy) { if (name) { delete name; //释放原来的内存 } name = new char[strlen(boy.name) + 1]; //分配新的内存 strcpy_s(name, strlen(boy.name) + 1, boy.name);
this->age = boy.age; this->salary = boy.salary; this->darkHorse = boy.darkHorse; //this->id = boy.id; //根据需求来确定是否要拷贝id return *this; }
bool Boy::operator>(const Boy& boy) { // 设置比较规则： // 薪资 * 黑马系数 + (100-年龄）*100 if (power() > boy.power()) { return true; } else { return false; } }
bool Boy::operator<(const Boy& boy) { if (power() < boy.power()) { return true; } else { return false; } }
bool Boy::operator==(const Boy& boy) { if (power() == boy.power()) { return true; } else { return false; } }
int Boy::operator[](std::string index) { if (index == AGE_KEY) { return age; } else if (index == SALARY_KEY) { return salary; } else if (index == DARK_HORSE_KEY) { return darkHorse; } else if (index == POWER_KEY) { return power(); } else { return -1; } }
int Boy::operator[](int index) { if (index == 0) { return age; } else if (index == 1) { return salary; } else if (index == 2) { return darkHorse; } else if (index == 3) { return power(); } else { return -1; } }
Boy::operator int() const { return power(); }
Boy::operator char* () const { return name; }
std::string Boy::description(void) { std::stringstream ret; ret << "ID:" << id << "\t姓名:" << name << "\t年龄:" << age << "\t薪资:" << salary << "\t黑马系数:" << darkHorse; return ret.str(); }
int Boy::power() const { // 薪资* 黑马系数 + (100 - 年龄） * 1000 int value = salary * darkHorse + (100 - age) * 100; return value; } |
main.cpp
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#include <iostream> #include "Boy.h"
using namespace std;
ostream& operator<<(ostream& os, const Boy& boy) { os << "ID:" << boy.id << "\t姓名:" << boy.name << "\t年龄:" << boy.age << "\t薪资:" << boy.salary << "\t黑马系数:" << boy.darkHorse; return os; }
istream& operator>>(istream& is, Boy& boy) { string name2; is >> name2 >> boy.age >> boy.salary >> boy.darkHorse; boy.name = (char*)malloc((name2.length() + 1) * sizeof(char)); strcpy_s(boy.name, name2.length() + 1, name2.c_str()); return is; }
int main() { Boy boy1("Rock", 28, 10000, 5); Boy boy2("Rock");
int power = boy1; char* name = boy2;
cout << power << endl; cout << name << endl;
system("pause"); return 0; } |
类类型A => 类类型B
调用对应的只有一个参数【参数的类型就是类类型A】的构造函数
也可以使用类型转换函数，但是使用对应的构造函数更合适。
实例：
把Boy类型，转换为Man类型
Boy.h
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#pragma once #include <string> #include <iostream>
#define AGE_KEY "age" #define SALARY_KEY "salary" #define DARK_HORSE_KEY "darkHorse" #define POWER_KEY "power"
typedef enum { AGE, SALARY, DARK_HORSE, POWER }BOY_KEY_TYPE;
using namespace std;
class Boy { public: //Boy(const char* name = NULL, int age = 0, int salary = 0, int darkHorse = 0); Boy(const char* name, int age, int salary, int darkHorse); ~Boy();
Boy(int salary); Boy(const char* name);
Boy& operator=(const Boy& boy);
bool operator>(const Boy& boy); bool operator<(const Boy& boy); bool operator==(const Boy& boy);
// 下标运算符的重载 int operator[](std::string index) const; int operator[](int index) const;
// 该方式不适合 //ostream& operator<<(ostream& os) const;
friend ostream& operator<<(ostream& os, const Boy& boy); friend istream& operator>>(istream& is, Boy& boy);
// 特殊的运算符重载：类型转换函数，不需要写返回类型 operator int() const; operator char* () const;
std::string description(void); private: char* name; int age; int salary; int darkHorse; //黑马值，潜力系数 unsigned int id; // 编号 static int LAST_ID;
int power() const; //综合能力值 };
ostream& operator<<(ostream& os, const Boy& boy); istream& operator>>(istream& is, Boy& boy); |
Boy.cpp
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#include "boy.h" #include <string.h> #include <sstream>
int Boy::LAST_ID = 0; //初始值是0
Boy::Boy(const char* name, int age, int salary, int darkHorse) { if (!name) { name = "未命名"; }
this->name = new char[strlen(name) + 1]; strcpy_s(this->name, strlen(name) + 1, name);
this->age = age; this->salary = salary; this->darkHorse = darkHorse; this->id = ++LAST_ID; }
Boy::~Boy() { if (name) { delete name; } }
Boy::Boy(int salary) { const char *defaultName = "未命名"; name = new char[strlen(defaultName) + 1]; strcpy_s(name, strlen(defaultName) + 1, defaultName);
age = 0; this->salary = salary; darkHorse = 0; this->id = ++LAST_ID; }
Boy::Boy(const char* name) { this->name = new char[strlen(name) + 1]; strcpy_s(this->name, strlen(name) + 1, name);
age = 0; this->salary = 0; darkHorse = 0; this->id = ++LAST_ID; }
Boy& Boy::operator=(const Boy& boy) { if (name) { delete name; //释放原来的内存 } name = new char[strlen(boy.name) + 1]; //分配新的内存 strcpy_s(name, strlen(boy.name) + 1, boy.name);
this->age = boy.age; this->salary = boy.salary; this->darkHorse = boy.darkHorse; //this->id = boy.id; //根据需求来确定是否要拷贝id return *this; }
bool Boy::operator>(const Boy& boy) { // 设置比较规则： // 薪资 * 黑马系数 + (100-年龄）*100 if (power() > boy.power()) { return true; } else { return false; } }
bool Boy::operator<(const Boy& boy) { if (power() < boy.power()) { return true; } else { return false; } }
bool Boy::operator==(const Boy& boy) { if (power() == boy.power()) { return true; } else { return false; } }
int Boy::operator[](std::string index) const { if (index == AGE_KEY) { return age; } else if (index == SALARY_KEY) { return salary; } else if (index == DARK_HORSE_KEY) { return darkHorse; } else if (index == POWER_KEY) { return power(); } else { return -1; } }
int Boy::operator[](int index)const { if (index == 0) { return age; } else if (index == 1) { return salary; } else if (index == 2) { return darkHorse; } else if (index == 3) { return power(); } else { return -1; } }
Boy::operator char* () const { return name; }
std::string Boy::description(void) { std::stringstream ret; ret << "ID:" << id << "\t姓名:" << name << "\t年龄:" << age << "\t薪资:" << salary << "\t黑马系数:" << darkHorse; return ret.str(); }
int Boy::power() const { // 薪资* 黑马系数 + (100 - 年龄） * 1000 int value = salary * darkHorse + (100 - age) * 100; return value; }
ostream& operator<<(ostream& os, const Boy& boy) { os << "ID:" << boy.id << "\t姓名:" << boy.name << "\t年龄:" << boy.age << "\t薪资:" << boy.salary << "\t黑马系数:" << boy.darkHorse; return os; }
istream& operator>>(istream& is, Boy& boy) { string name2; is >> name2 >> boy.age >> boy.salary >> boy.darkHorse; boy.name = (char*)malloc((name2.length() + 1) * sizeof(char)); strcpy_s(boy.name, name2.length() + 1, name2.c_str()); return is; } |
Man.h
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#pragma once #include <iostream>
using namespace std;
class Boy;
class Man { public: Man(const char *name, int age, int salary); Man(const Boy& boy); ~Man(); friend ostream& operator<<(ostream &os, const Man& man); private: char* name; int age; int salary; };
ostream& operator<<(ostream &os, const Man& man); |
Man.cpp
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#include "Man.h" #include "Boy.h" #include <string.h>
Man::Man(const char* name, int age, int salary) { if (!name) { name = "未命名"; }
this->name = new char[strlen(name) + 1]; strcpy_s(this->name, strlen(name) + 1, name);
this->age = age; this->salary = salary; }
Man::Man(const Boy& boy) { int len = strlen((char*)boy) + 1; name = new char[len]; strcpy_s(name, len, (char*)boy); age = boy[AGE]; salary = boy[SALARY]; }
Man::~Man() { delete name; }
ostream& operator<<(ostream &os, const Man& man) { os << "【男人】姓名:" << man.name << "\t年龄 : " << man.age << "\t薪资 : " << man.salary; return os; } |
main.cpp
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#include <iostream> #include "Boy.h" #include "Man.h" using namespace std; int main() { Boy boy("Rock", 28, 10000, 5); Man man = boy;
cout << boy << endl; cout << man << endl;
system("pause"); return 0; } |
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