第四章C++运算符重载详解.ppt

第四章 运算符重载 ;4.1什么是运算符重载;运算符重载的实质;;;;4.2运算符重载的方法;形式;4.4.1 重载为成员函数 ; class Complex { public: Complex(){real=0;imag=0;} Complex(double r,double i){real=r;imag=i;} Complex operator + (Complex c2); void display(); private: double real; double imag; }; Complex Complex::operator + (Complex c2) { Complex c; c.real=real+c2.real; c.imag=imag+c2.imag; return c; } ; void Complex::display() { cout(real,imagi)endl; } int main() { Complex c1(3,4),c2(5,-10),c3; c3=c1+c2; coutc1=;c1.display(); coutc2=;c2.display(); coutc1+c2=;c3.display(); return 0; } ;;;*;*;*;*;*;*;*;4.4.2运算符重载为友元函数;#include iostream.h class Complex { public: Complex () {real=0;imag=0;} Complex (double r) {real=r;imag=0;} Complex (double r,double i) {real=r;imag=i;} friend Complex operator+ (Complex c1, Complex c2); void display(); private: double real; double imag; };;;;;注意：;注意：;4.3 重载运算符的规则;4.3 重载运算符的规则;补充 关于返回值为对象类型和对象引用类型的区别;程序运行结果分析;程序运行结果分析;4.5重载双目运算符;;;;;;;;;;;;4.6重载单目运算符;;Time Time::operator ++() //前置单目运算符重载函数 { sec++; if(sec=60) { sec=sec-60; minute++; if(minute=60) { minute=minute-60; hour++; hour=hour%24; } } return *this; };;;;Time Time :: operator ++() //前置单目运算符重载函数 { sec++; if(sec=60) { sec=sec-60; minute++; if(minute=60) { minute=minute-60; hour++; hour=hour%24; } } return *this; };后置自增运算符的实现; int main() { Time time1(21,34,59),time2; cout time1 : ; time1.display(); ++time1; cout++time1: ; time1.display(); time2 = time1++; couttime1++: ; time1.display(); cout time2 : ; time2.display(); return 0; };4.7重载流插入运算符和流提取运算符;;4.7.1重载流插入运算符“” ;;;;4.7.2重载流提取运算符“”;;;;为什么输出流插入、输入流提取、不能定义为类的成员函数？;#include iostream using namespace std; class INT { int data; public: INT(int data = 10) :data(data){} INT oper