c++知识点----成员函数重载运算符

#define M 2
#include <iostream>
using namespace std;
#include "class.h"

int main()
{
	cout << "请输入4个数组成一个数组：\n";
	double arr[2][2];
	for (int i = 0; i < M; i++)
	{
		for (int j = 0; j < M; j++)
		{
			cin >> arr[i][j];
		}
	}
	Array arr1;//自动设置二维数组
	Array arr2(arr);//传递二维数组
	Array arr3 = arr1 + arr2;//加
	Array arr4 = arr2 - arr1;//减

	cout << "arr3:" << endl;
	arr3.show();
	cout << "arr4:" << endl;
	arr4.show();
	system("pause");
	return 0;
}

class .h

#pragma once
class Array
{
public:
	Array();//自动设置二维数组的所有值为1
	Array(const double p[][M]);//用户传递一个二维数组
	Array operator+(Array &);//两个数组相加
	Array operator-(Array &);//两个数组相减
	void show();//显示数组
private:
	double a[M][M];
};
Array::Array()
{
	for (int i = 0; i < M; i++)
	{
		for (int j = 0; j < M; j++)
		{
			a[i][j] = 1;
		}
	}
}
Array::Array(const double p[][M])
{
	for (int i = 0; i < M; i++)
	{
		for (int j = 0; j < M; j++)
		{
			a[i][j] = p[i][j];
		}
	}
}
Array Array::operator+(Array &B)//采用了用成员运算符重载，可以利用this指针减少一个参数
{
	Array A1;
	for (int i = 0; i < M; i++)
	{
		for (int j = 0; j < M; j++)
		{
			A1.a[i][j] = a[i][j]+B.a[i][j];//a[i][j]之所以不用指定对象，是因为this指针就指向“+”号的左操作数 
		}
	}
	return A1;
}
Array Array::operator-(Array &B)
{
	Array A1;
	for (int i = 0; i < M; i++)
	{
		for (int j = 0; j < M; j++)
		{
			A1.a[i][j] =a[i][j] -B.a[i][j];
		}
	}
	return A1;
}
void Array::show()
{
	for (int i = 0; i < M; i++)
	{
		for (int j = 0; j < M; j++)
		{
			cout << a[i][j]<<" ";
		}
		cout << '\n';
	}
}