时间:2019年8月22日21:24:39
编译器:vs2017
1.加号运算符重载
2. 递增运算符重载
3. 左移运算符重载
4. 赋值运算符重载
5. 关系运算符重载
6. 函数调用运算符重载
加号运算符重载
#include <iostream>
#include <cmath>
using namespace std;
//运算符重载概念:对已有的运算符重新进行定义,赋予其另一种功能,以适应不同的数据类型
// 加号运算符重载
class Person
{
public:
// 1、成员函数重载+号
//Person operator+(Person &p)
//{
// Person temp;
// temp.m_A = this->m_A + m_A;
// temp.m_B = this->m_B + m_B;
// return temp;
//}
int m_A;
int m_B;
};
// 2、全局函数重载+号
Person operator+(Person &p1, Person &p2)
{
Person temp;
temp.m_A = p1.m_A + p2.m_A;
temp.m_B = p1.m_B + p2.m_B;
return temp;
}
// 函数重载版本
Person operator+(Person &p1, int num)
{
Person temp;
temp.m_A = p1.m_A + num;
temp.m_B = p1.m_B + num;
return temp;
}
void test01()
{
Person p1;
p1.m_A = 10;
p1.m_B = 10;
Person p2;
p2.m_A = 20;
p2.m_B = 20;
Person p3;
p3 = p1 + p2; //开始的报错是因为编译器不知道这种运算规则
// 1、成员函数重载本质调用:Person p3 = p1.operator + (p2);
// 2、全局函数的调用本质:Person p3 = operator+(p1, p2);
Person p4 = p1 + 100; //Person + int
cout << " p3.m_A = " << p3.m_A << endl;
cout << " p3.m_B = " << p3.m_B << endl;
cout << " p4.m_A = " << p4.m_A << endl;
cout << " p4.m_B = " << p4.m_B << endl;
}
int main()
{
test01();
system("pause");
return 0;
}
递增运算符重载
#include <iostream>
using namespace std;
// 重载递增运算符
//自定义类型
class MyInteger
{
friend ostream & operator<<(ostream& cout, MyInteger myint);
public:
MyInteger()
{
m_Num = 0;
}
// 重载前置++运算符
MyInteger& operator++() //前置递增返回引用
{
// 先进行++运算符
m_Num++;
// 再将自身做返回
return *this;
}
// 重载后置++运算符
//void operator++(int) int 代表占位参数, 可以用于区分前置和后置递增
MyInteger operator++(int) //后置递增返回值
{
// 先 记录当时的结果
MyInteger temp = *this;
// 后递增
m_Num++;
//最后将记录结果做返回
return temp;
}
private:
int m_Num;
};
// 重载 << 运算符
ostream & operator<<(ostream& cout, MyInteger myint)
{
cout << myint.m_Num;
return cout;
}
void test01()
{
MyInteger myint;
cout << ++(++myint) << endl;
cout << myint << endl;
}
void test02()
{
MyInteger myint;
cout << myint++ << endl;
cout << myint << endl;
}
int main()
{
test01();
test02();
system(" pause ");
return 0;
}
左移运算符重载
#include <iostream>
using namespace std;
#include <string>
// 左移运算符重载
class Person
{
public:
//利用成员函数重载 左移运算符 p.operator<<(cout) 简化版 p << cout
//不会利用成员函数重载<<运算符, 因为无法实现 cout在左侧
//void operator<<( cout )
//{
//
//}
int m_A;
int m_B;
};
//只能利用全局函数重载左移运算符
ostream &operator<<(ostream &cout, Person &p) //本质 operator<< (cout, p) 简化 cout << p
{
cout << " m_A = " << p.m_A << " m_B = " << p.m_B;
return cout;
}
void test01()
{
Person p;
p.m_A = 10;
p.m_B = 10;
cout << p << " 里昂 " << endl;
}
int main()
{
test01();
system("pause");
return 0;
}
赋值运算符重载
#include <iostream>
using namespace std;
/*
1. 默认构造函数(无参,函数体为空)
2. 默认析构函数(无参,函数体为空)
3. 默认拷贝构造函数,对属性进行值拷贝
4. 赋值运算符 operator=, 对属性进行值拷贝
*/
class Person
{
public:
Person(int age)
{
m_Age = new int(age);
}
~Person()
{
if (m_Age != NULL)
{
delete m_Age;
m_Age = NULL;
}
}
// 重载 赋值运算符
Person &operator=(Person &p)
{
// 编译器是提供浅拷贝
//m_Age = p.m_Age;
// 应该先判断是否有属性在堆区, 如果有先释放干净, 然后在深拷贝
if (m_Age != NULL)
{
delete m_Age;
m_Age = NULL;
}
m_Age = new int(*p.m_Age);
// 返回对象本身
return *this;
}
int *m_Age;
};
void test01()
{
Person p1(18);
Person p2(20);
Person p3 = p2 = p1; //赋值操作
p1 = p2; //赋值操作
cout << " p1 = " << *p1.m_Age << endl;
cout << " p2 = " << *p2.m_Age << endl;
cout << " p3 = " << *p3.m_Age << endl;
}
int main()
{
//test01();
system("pause");
return 0;
}
关系运算符重载
#include <iostream>
using namespace std;
#include <string>
class Person
{
public:
Person(string name,int age)
{
m_Name = name;
m_Age = age;
}
// 关系运算符重载
bool operator==(Person &p)
{
if (this->m_Name == p.m_Name && this->m_Age == p.m_Age)
{
return true;
}
else
return false;
}
private:
string m_Name;
int m_Age;
};
void test01()
{
Person p1(" 里昂 ", 22);
Person p2(" 花生 ", 22);
if (p1 == p2)
{
cout << " p1 和 p2 是相等的!" << endl;
}
else
cout << " p1 和 p2 是不相等的!" << endl;
}
int main()
{
test01();
system("pause");
return 0;
}
函数调用运算符重载
#include <iostream>
using namespace std;
#include <string>
/*
* 函数调用运算符 () 也可以重载
* 由于重载后使用的方式非常像函数的调用,因此称为仿函数
* 仿函数没有固定写法,非常灵活
*/
class MyPrint
{
public:
// 重载函数调用运算符
void operator()(string test)
{
cout << test << endl;
}
};
void MyPrint02(string test)
{
cout << test << endl;
}
void test01()
{
MyPrint myPrint;
myPrint(" leno "); // 由于使用起来非常类似于函数调用, 因此称为仿函数
MyPrint02(" peanute "); //函数调用
}
// 仿函数没有固定写法,非常灵活
// 加法类
class MyAdd
{
public:
int operator()(int num1, int num2)
{
return num1 + num2;
}
};
void test02()
{
MyAdd add;
add(1, 2);
cout << add(1, 2) << endl;
//匿名函数对象
cout << MyAdd()(1, 2) << endl;
}
int main()
{
test02();
system("pause");
return 0;
}