8_1.cpp

来自「c++书籍的源代码」· C++ 代码 · 共 62 行

#include<iostream.h>
 class fraction
{
 public:
	fraction(int x=1,int y=1);
    fraction& operator +(fraction& c);//运算符+重载为成员函数
    fraction& operator ++(void);//前缀运算符++重载为成员函数
    fraction& operator ++(int);//后缀运算符++重载为成员函数
	void display(void);
 private:
	int a;
	int b;
};
 fraction::fraction(int x,int y)
{
	if(y==0)
	 b=1;
	else
	 b=y;
	a=x;
    cout<<"构造函数被调用"<<endl;
}
 fraction& fraction::operator +(fraction& c)
{
	int m,n;
	n=b*c.b;
	m=a*c.b+b*c.a;
    return(fraction(m,n));
}
 fraction& fraction::operator ++(void)
{
	a=a+b;
	cout<<"前缀运算符++"<<endl;
	return(*this);
}
 fraction& fraction::operator ++(int)
{
	fraction temp;
	temp=*this;
	a=a+b;
	cout<<"后缀运算符++"<<endl;
	return(temp);
}
 void fraction:: display(void)
{
	cout<<a<<"/"<<b<<endl;
}
 int main()
{
    fraction x(3,4),y(1,2),z;
	z=x+y;
	z.display();
	z=++x;
	x.display(); 
    z.display();
	z=y++;
    y.display(); 
	z.display();
	return(0);
}