---------- study notes C ++ overload operators

C ++ allowed to be overloaded operator is different from the C language is a major optimization function, but it also has its own limitations, let us together look!

Experiment 1: define a plurality of class Complex, overloading, "+" operator, so that it can be used to increase since i.e. real and imaginary part of the complex respectively incremented and the member function implemented; Overload "+" and "- "operator, so that it can be used for addition and subtraction of a plurality of complex, the UF element function implementation.

• Overloaded "+" operator: with member functions to achieve:

#include <iostream>
using namespace std;

class Complex
{

private:

	int real,imag;

public:

	Complex(){real=0;imag=0;}//无参构造函数

	Complex(int r,int i){real=r;imag=i;}//有参构造函数

	void print()
	{
		cout<<real;
		if(imag>=0)
		{cout<<"+";}
	    cout<<imag<<"i"<<endl;
	}

	//前置自增
    Complex operator++()
	{
		Complex c;
		c.real=++(this->real);
		c.imag=++imag;
		return c;
	}

	//后置自增
	Complex operator++(int)	
	{
		/*Complex c;
		c.real=(this->real)++;
		c.imag=imag++;
		return c;*/
		Complex c=*this;
		real++;
		imag++;
		return c;
	}

};

int main()
{

	Complex c1(1,1),c2(2,-2),c3,c4,c5;
	c1.print();
	c3.print();
	c4=c2++;
	c5=++c1;//成员函数实现 c1.operator++() this
	c4.print();
	c5.print();
	
	return 0;
}

• Overloaded "+" and "-" operator: UFIDA member function to achieve:

#include <iostream>
using namespace std;

class Complex
{

private:

	int real,imag;
public:

	Complex(){real=0;imag=0;}//无参构造函数

	Complex(int r,int i){real=r;imag=i;}//有参构造函数

	friend Complex operator-(Complex cc1,Complex cc2)//c4=c1-c2
	{
		Complex c;
		c.real=cc1.real-cc2.real;
		c.imag=cc1.imag-cc2.imag;
		return c;
	}
/*
friend Complex operator-(Complex &cc1,Complex &cc2)//c4=c1-c2
	{
		return Complex(cc1.real-cc2.real ,cc1.imag -cc2.imag );
	}
	*/
	
	friend Complex operator+(Complex cc1,Complex cc2)//c5=c1+c2
	{
		Complex c;
		c.real=cc1.real+cc2.real;
		c.imag=cc1.imag+cc2.imag;
		return c;
	}

	void print()
	{
		cout<<real;
		if(imag>=0){cout<<"+";}
		cout<<imag<<"i"<<endl;
	}
	
};

int main()
{
	Complex c1(1,1),c2(2,-2),c3,c4,c5;
	c1.print();
	c3.print();
	c4=c1-c2;//operator-(c1,c2);
	c4.print();
	c5=c1+c2;//operator+(c1,c2);
	c5.print();
	return 0;
}

Experiment 2:
programming, Overload operator "+" and "-", two of the matrices of addition, subtraction.

#include <iostream>
using namespace std;
int i,j;

class Matrix
{

private:

	int matrix[3][3];

public:

	void show();

	Matrix();//无参构造函数

	Matrix operator + (Matrix &m1);
	Matrix operator - (Matrix &m1);
};

Matrix::Matrix()
{
	for(i=0;i<3;i++)
		for(j=0;j<3;j++)
			matrix[i][j]=rand()%20;
}

Matrix Matrix::operator+(Matrix &m1)
{
	Matrix tmp;
	for( i=0;i<3;i++)
		for( j=0;j<3;j++)
			tmp.matrix [i][j]=matrix[i][j]+m1.matrix [i][j];
	return tmp;
}

Matrix Matrix::operator-(Matrix &m1)
{
	Matrix tmp;
	for( i=0;i<3;i++)
		for( j=0;j<3;j++)
			tmp.matrix [i][j]=matrix[i][j]-m1.matrix [i][j];
	return tmp;
}

void Matrix::show()
{
	for(i=0;i<3;i++)
	{
		for(j=0;j<3;j++)
			cout<<matrix[i][j]<<'\t';
		cout<<endl;
	}
	cout<<endl;
}

void main()
{
	Matrix m1,m2,m3,m4;
	m3=m1+m2;
	m4=m1-m2;
	m1.show ();
	m2.show();
	cout<<"Matrix m1+m2="<<endl;
	m3.show ();
	cout<<"Matrix m1-m2="<<endl;
	m4.show ();
	return ;
}