工厂方法模式
和简单工厂的不同之处：
把逻辑判断从工厂类中移到客户端。
工厂类下多了几个子类用来创建对应的进行实际操作的
子类对象。1
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144/*
* FactoryMethod.cpp
*
* 工厂方法模式
* Created on: 2016年3月13日 下午8:56:50
* Author: Wayne 13186259527@163.com
*/
#include <iostream>
#include <stdlib.h>
using namespace std;
class Operation {
private:
double x, y;
char c;
public:
Operation() {
}
Operation(double x, double y, char c) {
this->x = x;
this->y = y;
this->c = c;
}
virtual double Calc(double x, double y) {
return 0;
}
;
double GetX() {
return this->x;
}
double GetY() {
return this->y;
}
char GetC() {
return this->c;
}
};
class Add: public Operation {
public:
Add() {
}
;
double Calc(double x, double y) {
return x + y;
}
};
class Sub: public Operation {
public:
Sub() {
}
;
double Calc(double x, double y) {
return x - y;
}
};
class Mul: public Operation {
public:
Mul() {
}
;
;
double Calc(double x, double y) {
return x * y;
}
};
class Div: public Operation {
public:
Div() {
}
;
double Calc(double x, double y) {
if (y == 0) {
cout << "0不能作为被除数" << endl;
exit(0);
}
return x / y;
}
};
class Factory {
public:
virtual Operation* CreateOperation() {
return NULL;
}
;
};
class AddFactory: public Factory {
public:
Operation* CreateOperation() {
return new Add();
}
};
class SubFactory: public Factory {
public:
Operation* CreateOperation() {
return new Sub();
}
};
class MulFactory: public Factory {
public:
Operation* CreateOperation() {
return new Mul();
}
};
class DivFactory: public Factory {
public:
Operation* CreateOperation() {
return new Div();
}
};
int main(void) {
cout << "hello world" << endl;
cout << "eg:5+8" << endl;
double x, y;
char c;
cin >> x >> c >> y;
double result;
Factory *f = NULL;//指向对应的工厂
Operation *p = NULL;//指向对应的实现方法的子类
switch (c) {
case '+':
f = new AddFactory();
break;
case '-':
f = new SubFactory();
break;
case '*':
f = new MulFactory();
break;
case '/':
f = new DivFactory();
break;
}
p = f->CreateOperation();
result = p->Calc(x, y);
cout << "result = " << result << endl;
return 0;
}