->用在指標型別的類例項的，而.用在例項化物件的指向。

下面是例子

#include <iostream>
using namespace std;
class Complex
{
private:
	double real;
	double image;
public:
	Complex()
	{
		this->image=0;
		this->real=0;
	}
	Complex(double real,double image)
	{
		this->real=real;
		this->image=image;
	}
	friend Complex operator+(Complex com1,Complex com2);
	void show();
};
Complex operator+(Complex com1,Complex com2)
{
	return Complex(com1.real+com2.real,com1.image+com2.image);
	//下面是錯誤的
	//return Complex(com1->real+com2->real,com1->image+com2->image);
}
void Complex::show()
{
	cout<<"實數部分為"<<this->real<<endl;
	cout<<"虛數部分為"<<this->image<<endl;
	//下面是錯誤的
	//cout<<"實數部分為"<<this.real<<endl;
	//cout<<"虛數部分為"<<this.image<<endl;
}
int main()
{
	Complex com1(2,5),com2(3,9),sum;
	sum=com1+com2;
	sum.show();
	system("pause");
	return 1;
}