简单工厂模式

  1 #include <iostream>
  2 #include <string>
  3 using namespace std;
  4 
  5 /*
  6  * 运算基类
  7  */
  8 class Operation
  9 {
 10 public:
 11     double numberA;
 12     double numberB;
 13 public:
 14     virtual double  getResult()
 15     {
 16         return 0;
 17     }
 18 };
 19 
 20 /*
 21  * 加法运算子类
 22  */
 23 class addOperation : public Operation
 24 {
 25     double getResult()
 26     {
 27         return numberA + numberB;
 28     }
 29 };
 30 
 31  /*
 32   * 减法运算子类
 33   */
 34 class subOperation : public Operation
 35 {
 36     double getResult()
 37     {
 38         return numberA - numberB;
 39     }
 40 };
 41 
 42  /*
 43   * 乘法运算子类
 44   */
 45 class mulOperation : public Operation
 46 {
 47     double getResult()
 48     {
 49         return numberA * numberB;
 50     }
 51 };
 52 
 53  /*
 54   * 除法运算子类
 55   */
 56 class divOperation : public Operation
 57 {
 58     double getResult()
 59     {
 60         return numberA / numberB;
 61     }
 62 };
 63 
 64  /*
 65   * 简单构建工厂
 66   */
 67 class operFactory
 68 {
 69 public:
 70     static Operation *createOperation(char c)
 71     {
 72         switch (c)
 73         {
 74         case ‘+‘:
 75             return new addOperation;
 76             break;
 77         case ‘-‘:
 78             return new subOperation;
 79             break;
 80         case ‘*‘:
 81             return new mulOperation;
 82             break;
 83         case ‘/‘:
 84             return new divOperation;
 85             break;
 86         default:
 87             break;
 88         }
 89     }
 90 };
 91 
 92  /*
 93   * 客户端应用示例
 94   */
 95 void main()
 96 {
 97     Operation *oper = operFactory::createOperation(‘+‘);
 98     oper->numberA = 9;
 99     oper->numberB = 99;
100     cout << oper->getResult() << endl;
101 }