Simple Factory mode with C + + learning design pattern

</pre> got the book "Big Talk Design Mode", which, judging from the style of the book, feels that the book is well suited for college education. But for beginners, C # is not easy to accept. In order to solve this problem, and in order to improve their C + + level and deepen the understanding of object-oriented, I decided to use C + + to learn this book. <p></p><p><span style= "WHITE-SPACE:PRE;" > Operation class header file </span></p><p><span style= "WHITE-SPACE:PRE;" ></span></p><pre name= "code" class= "CPP" > #ifndef operation_h#define operation_hclass OPERATION {Public    :        operation ();        Virtual ~operation ();        void Set_numbera (double _numbera);        void Set_numberb (double _numberb);        Double Get_numbera ();        Double Get_numberb ();        Double virtual  get_result ();    Protected:        double Numbera;        Double Numberb;    Private:}; #endif//Operation_h

Operation class. cpp file

#include "Operation.h" operation::operation () {    //ctor    numbera = 0;    Numberb = 0;} Operation::~operation () {    //dtor}void Operation::set_numbera (double _numbera) {    numbera = _numbera;} void Operation::set_numberb (double _numberb) {    numberb = _numberb;} Double Operation::get_numbera () {    return this->numbera;} Double Operation::get_numberb () {    return this->numberb;} Double   Operation::get_result () {    return 0.0;}

Then the + 、-、 *,/Four classes inherit the class of operations respectively

#ifndef operationadd_h#define operationadd_h#include "Operation.h" class Operationadd:public operation{public    :        double Get_result ();    Protected:    private:}; #endif//Operationadd_h

#include "OperationAdd.h" double Operationadd::get_result () {    double result = 0;    result = Numbera + Numberb;    return result;}

#ifndef operationsub_h#define operationsub_h#include "Operation.h" class Operationsub:public operation{public    :        double Get_result ();    Protected:    private:}; #endif//Operationsub_h

#include "OperationSub.h" double Operationsub::get_result () {    double result = 0;    result = Numbera-numberb;    return result;}

#ifndef operationmul_h#define operationmul_h#include "Operation.h" class Operationmul:public operation{public    :        double Get_result ();    Protected:    private:}; #endif//Operationmul_h

#include "OperationMul.h" double Operationmul::get_result () {    double result = 0;    result = Numbera*numberb;    return result;}

#ifndef operationdiv_h#define operationdiv_h#include "Operation.h" class Operationdiv:public operation{public    :        double Get_result ();    Protected:    private:}; #endif//Operationdiv_h

#include "OperationDiv.h" double Operationdiv::get_result () {    double result = 0;    result = Numbera/numberb;    return result;}

Then there was a factory class

#ifndef operationfactory_h#define operationfactory_h#include "Operation.h" #include "OperationAdd.h" #include " OperationSub.h "#include" OperationMul.h "#include" OperationDiv.h "class operationfactory{public    :        static Operation *createoperation (char ch);        Operationfactory ();        Virtual ~operationfactory ();    Protected:    private:}; #endif//Operationfactory_h

#include "OperationFactory.h" Operationfactory::operationfactory () {    //ctor}operationfactory::~ Operationfactory () {    //dtor}operation *operationfactory::createoperation (char ch) {    operation *oper;    Switch (CH) {case    ' + ':        oper = new Operationadd ();        break;    Case '-':        oper = new Operationsub ();        break;    Case ' * ':        oper = new Operationmul ();        break;    Case '/':        oper = new Operationdiv ();        break;    }    return oper;}

And finally the main class

#include <iostream> #include "Operation.h" #include "OperationAdd.h" #include "OperationSub.h" #include " OperationMul.h "#include" OperationDiv.h "#include" OperationFactory.h "using namespace Std;int Main () {    operation* Oper;    Oper = operationfactory::createoperation (' * ');    Oper->set_numbera (1);    Oper->set_numberb (2);    Cout<<oper->get_result ();    return 0;}

Simple Factory mode with C + + learning design pattern