java - 检查温度条件

Question

如何在这三个条件下设置合适的温度，至少在 98°C、99°C、1°C 和 2°C 等？

package boiling.freezing;

import java.util.Scanner;

public class BoilingFreezing {

    public static void main(String[] args) {
        System.out.println("Give the temperature : ");
        Scanner sc = new Scanner(System.in);
        int temp = sc.nextInt();
        if (temp >= 100){
            System.out.println("The water is boiling!");
        }
        else if (temp <= 0){
            System.out.println("The water is freezing!");
        }
        else{
            System.out.println("The water is at normal_state!");
        }
    } 
}

Answer 1

我将向您提供一个模式，而不是一个简单的if-elseif-else block 。

您可能想要一个接口(interface)温度

interface Temperature {
   /** Returns true if the temperature matches the criteria. */
   boolean within(final int temperature);

   /** Returns an appropriate, descriptive, message. */
   String message();
}

然后您可以实现此接口(interface)来满足您的多个条件

class BoilingTemperature implements Temperature {
   public boolean within(final int temperature) {
      return temperature > 99;
   }

   public String message() {
      return "Water boiling";
   }
}

class FreezingTemperature implements Temperature {
   public boolean within(final int temperature) {
      return temperature < 1; // Should be 3 degree! But anyway.
   }

   public String message() {
      return "Water freezing";
   }
}

您可以使用此模式编写自定义温度处理程序

class YourCustomTemperature implements Temperature {
   public boolean within(final int temperature) {
      return temperature > 6 && temperature < 40;
   }

   public String message() {
      return "Your custom message";
   }
}

您需要维护这些具体实现的列表并循环它们以检查哪些匹配。

final List<Temperature> temperatures = new ArrayList<>(6);
temperatures.add(new BoilingTemperature());
temperatures.add(new FreezingTemperature());
temperatures.add(new YourCustomTemperature());
...

然后

public static void main(String[] args) {
    System.out.println("Give the temperature : ");
    final Scanner sc = new Scanner(System.in);
    int temp = sc.nextInt();

    for (final Temperature t : temperatures) {
       if (t.within(temp)) {
          System.out.println(t.message());
       } 
    }
}