C++ 简单工厂模式的实现

作笔记使用，如有写的不好或者不够精妙的，还请指正！！如果觉得有帮助也可以三连一波，多谢！

#include
using namespace std;

 

class Caculator {
public:
	virtual int caculate(int a, int b) = 0; // 设为纯虚函数，子类必须重写
};

class Add : public Caculator {
public:
	int caculate(int a, int b) {
		return a + b;
	}
};

class Minus : public Caculator {
public:
	int caculate(int a, int b) {
		return a - b;
	}
};

class Multiply : public Caculator {
public:
	int caculate(int a, int b) {
		return a * b;
	}
};

class Divide : public Caculator {
public:
	int caculate(int a, int b) {
		return a / b;
	}
};

// 工厂类
class Factory {
public:
	// 返回一个父类指针指向子类对象(多态的实现)
	Caculator* create_caculator(char ch) { 
		switch (ch) {
		case 'a':
			return new Add();
		case 'b':
			return new Minus();
		case 'c':
			return new Multiply();
		case 'd':
			return new Divide();
		default:
			cout << "ERROR" << endl;	
			return nullptr;
		}
	}
};

int main() {
	// 检验功能
	int a = 10, b = 2;
	Factory factory;
	Caculator* add = factory.create_caculator('a');
	Caculator* minus = factory.create_caculator('b');
	Caculator* multiply = factory.create_caculator('c');
	Caculator* divide = factory.create_caculator('d');
	cout << add->caculate(a, b) << endl;
	cout << minus->caculate(a, b) << endl;
	cout << multiply->caculate(a, b) << endl;
	cout << divide->caculate(a, b) << endl;
	return 0;
}

溜了溜了~~~~~