1.重载加法运算符
为什么要重载加法运算符？
因为C++提供的加法运算符只能满足基本数据类型间的加法，如果我想让俩个相同的类的对象进行加法的话会报错
所以为了能让俩个相同类的对象进行加法，我们要把这个过程封装到一个函数里面，只不过要多加一个关键字operator而已，让编译器一下子就找到，这个是重载运算符的函数
作用：实现俩个自定义运算符相加
成员函数实现运算符重载
#include <iostream>
using namespace std;
class Box {int length;int width;int height;
public:Box() {length = 0;width = 0;height = 0;}Box(int length,int width,int height) {this->length = length;this->width = width;this->height = height;}Box(const Box& other) {length = other.length;width = other.width;height = other.height;}//成员函数重载加法运算符Box operator+(const Box& other) {Box p;p.length = this->length + other.length;p.width = this->width + other.width; p.height = this->height + other.height;return p;}
};
int main() {Box a(1,2,3);Box b(2, 3, 4);Box c = a + b;//直接调用Box d;d = a.operator+(b);//调用重载运算符的函数return 0;
}
全局函数实现运算符的重载
#include <iostream>
using namespace std;
class Box {int length;int width;int height;friend Box operator+(const Box& other1, const Box& other2);friend Box operator+(const Box& other1, int val);
public:Box() {length = 0;width = 0;height = 0;}Box(int length,int width,int height) {this->length = length;this->width = width;this->height = height;}Box(const Box& other) {length = other.length;width = other.width;height = other.height;}
};
//全局函数重载加法运算符
Box operator+(const Box& other1,const Box& other2) {//不调用成员函数是无法访问私有的成员变量的，需要设置为友元，告诉编译器，我这个重载运算符的函数是你这个类的好朋友，都哥们，能fBox p;p.length = other1.length + other2.length;p.width = other1.width + other2.width;p.height = other1.height + other2.height;return p;
}
Box operator+(const Box& other1,int val) {Box p;p.length = other1.length + val;p.width = other1.width + val;p.height = other1.height + val;return p;
}
int main() {Box a(1,2,3);Box b(2, 3, 4);Box c = a + b;Box d;d=operator+(a,b);return 0;
}
