阅读下列说明和C++代码,将应填入(n)处的字句写在答题纸的对应栏内. 【说明】 某实验室欲建立
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阅读下列说明和C++代码,将应填入 (n)处的字句写在答题纸的对应栏内. 【说明】 某实验室欲建立一个实验室环境监测系统,能够显示实验室的温度、湿度以及洁净度等环境数据。当获取到最新的环境测量数据时,显示的环境数据能够更新。 现在采用观察者(Observer)模式来开发该系统。观察者模式的类图如图5-1所示。 【C++代码】 include <iostream> include <vector> using namespace std; class Observer { public: virtual void update(float temp, float humidity, float cleanness)=0; }; class Subject { public: virtual void registerObserver(Observer* o) = 0; //注册对主题感兴趣的观察者 virtual void removeObserver(Observer* o) = 0; //删除观察者 virtual void notifyObservers() = 0;//当主题发生变化时通知观察者 }; class EnvironmentData : public (1) { private: vector<Observer*> observers; float temperature, humidity, cleanness; public: void registerObserver(Observer* o) { observers.push_back(o); } void removeObserver(Observer* o) { /* 代码省略 */ } void notifyObservers() { for(vector<Observer*>::const_iterator it = observers.begin(); it != observers.end(); it++) { (2) ; } } Void measurementsChanged() { (3) ; } void setMeasurements(float temperature, float humidity, float cleanness) { this->temperature = temperature; this->humidity = humidity; this->cleanness = cleanness; (4) ; } }; class CurrentConditionsDisplay : public (5) { private: float temperature, humidity, cleanness; Subject* envData; public: CurrentConditionsDisplay(Subject* envData) { this->envData = envData; (6) ; } void update(float temperature, float humidity, float cleanness) {this->temperature = temperature; this->humidity = humidity; this->cleanness = cleanness; display(); } void display() { /* 代码省略 */ } }; int main() { EnvironmentData* envData = new EnvironmentData(); CurrentConditionsDisplay* currentDisplay = new CurrentConditionsDisplay(envData); envData->setMeasurements(80, 65, 30.4f); return 0; } 请帮忙给出正确答案和分析,谢谢!答案
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