C + + Fifth day Note February 22, 2016 (Monday) p.m.

1. Output operator Overloading:

1#include <iostream>2#include"CString"3 4 using namespacestd;5 6 classComplex7 {8  Public:9Complex (intR=0,intI=0): _r (R), _i (i) {}Ten     voidprint (); OneFriend ostream&operator<< (ostream& out,Constcomplex&_c); A Private: -     int_r; -     int_i; the }; -  -ostream&operator<< (ostream& out,Constcomplex&_c) { -      out<<"_r="<<_c._r<<"_i="<<_c._i<<Endl; +     return  out; - } + //cout<<c<<2 data into cout buffer ostream printf istream:cin A  at //The return value type is not const-decorated and is typically used by friends -  - //return value Why use the &:ostream class only and have only one object.  -  - //Why the return value cannot be const-decorated: COUT<<C1<<C2 - //if the return value is const-decorated, you cannot continue writing to the cout for output data.  in //eg:cout<<c; // Right - //cout<<c<<endl; //Error to  + //the second parameter,:const&, can receive either a const object or a non-const object.  - //cannot exist as a member function because the first operand can only be a ostream type unique object cout and cannot be a custom type object.  the voidComplex::p rint () * { $     if(_i==0) {Panax Notoginsengcout<<_r<<Endl; -     } the     Else if(_i<0){ +cout<<_r<<_i<<"I"<<Endl; A     } the     Else +cout<<_r<<"+"<<_i<<"I"<<Endl; - } $ intMainintargcConst Char*argv[]) { $cout<<"c1="; -Complex C1 (3,2); - c1.print (); thecout<<C1; -     return 0;Wuyi}

2. Subscript operator Overloading:

1#include <iostream>2#include"CString"3 #defineSize 54 using namespacestd;5 6 classVector7 {8  Public:9     Const int&operator[](intIndexConst//Const Version: values that focus on reading elementsTen     { One         returnRep[index]; A     } -     int&operator[](intIndex//Non-const version: Focus on writing, modifying the value of an element -     { the         returnRep[index]; -     } - Private: -     intRep[size];//return value type: The element type in the container.  + }; -  +ostream&operator<< (ostream& out,Constvector&a) A { at      for(intI=0; i<size; i++) { -          out<<a[i]<<" ";//using the const version of the compiler calls the subscript overloaded function.  -     } -     return  out; - } -  in  - intMainintargcConst Char*argv[]) { to Vector x; +cout<<"Enter"<<size<<"integers.\n"; -      for(intI=0; i<size; i++) { theCin>>X[i]; *     } $     ConstVector y=x;Panax Notoginsengcout<<"x:"<<x<<Endl; -cout<<"y:"<<y<<Endl; thex[0]= -; +cout<<"x:"<<x<<Endl; Acout<<"y:"<<y<<Endl; the     return 0; +}

C + + Fifth day Note February 22, 2016 (Monday) p.m.