小编Amj*_*kir的帖子

在本文中,作者选择返回类型为类类型http://www.learncpp.com/cpp-tutorial/92-overloading-the-arithmetic-operators/ 强调文本,我们只需将返回类型更改为返回int ,因为我想做以下,我试过这个,它只是工作正常,为什么作者做了返回类型类？

#include <cstdlib>
#include <iostream>
using namespace std;
class Cents // defining new class
{
    private:
    int m_Cents;
    int m_Cents2;
    public:
    Cents(int Cents=0, int Cents2=0) // default constructor
    { 
        m_Cents=Cents;
        m_Cents2=Cents2;
}
Cents(const Cents &c1) {m_Cents = c1.m_Cents;}
friend ostream& operator<<(ostream &out, Cents &c1); //Overloading << operator
friend int operator+(const Cents &c1, const Cents &c2); //Overloading + operator
};
ostream& operator<<(ostream &out, Cents &c1)
{
out << "(" << c1.m_Cents << " , " << c1.m_Cents2 …