第四章第二十四题（对三个城市排序）(Sort three cities)

*4.24（对三个城市排序）编写一个程序，提示用户输入三个城市名称，然后以升序进行显示。

下面是一个运行示例：
Enter the first city:
Enter the second city:
Enter the third city:
The three cities in alphabetical order are Atlanta Chicago Los Angeles

*4.24(Sort three cities) Write a program that prompts the user to enter three cities and displays them in alphabetical order.

Here is a sample run:
Enter the first city:
Enter the second city:
Enter the third city:
The three cities in alphabetical order are Atlanta Chicago Los Angeles

下面是参考答案代码:

import java.util.*;

public class  SortThreeCitiesQuestion24 {
  public static void main(String[] args) {
    String city1,city2,city3;
    
    Scanner inputScanner = new Scanner(System.in);
    
    System.out.print("Enter the first city: ");
    city1 = inputScanner.nextLine();
    System.out.print("Enter the second city: ");
    city2 = inputScanner.nextLine();
    System.out.print("Enter the third city: ");
    city3 = inputScanner.nextLine();
    
    if(city1.compareTo(city2) > 0) // city1 > city2
    {
      if(city2.compareTo(city3) > 0) // city2 > city3
        System.out.println("The three cities in alphabetical order are " + city1 + " " + city2 + " " + city3);
      else //city2 < city3
      {
        if(city1.compareTo(city3) > 0) // city1 > city3
          System.out.println("The three cities in alphabetical order are " + city2 + " " + city3 + " " + city1);
        else // city1 < city3
          System.out.println("The three cities in alphabetical order are " + city2 + " " + city1 +  " " + city3);
      }
    }
    else // city1 < city2
    {
      if(city1.compareTo(city3) > 0) // city1 > city3
        System.out.println("The three cities in alphabetical order are " + city3 + " " + city1 + " " + city2);
      else //city1 < city3
      {
        if(city2.compareTo(city3) > 0) // city2 > city3
          System.out.println("The three cities in alphabetical order are " + city1 + " " + city3 + " " + city2);
        else // city2 < city3
          System.out.println("The three cities in alphabetical order are " + city1 + " " + city2 + " " + city3);
      }
    }
    
    inputScanner.close();
  }
}

运行效果：

注：编写程序要养成良好习惯
1.文件名要用英文，具体一点
2.注释要英文
3.变量命名要具体，不要抽象（如:a,b,c等等），形式要驼峰化
4.整体书写风格要统一（不要这里是驼峰，那里是下划线，这里的逻辑段落空三行，那里相同的逻辑段落空5行等等）
5.普通变量，方法名要小驼峰，类名要大驼峰，常量要使用全部大写加上下划线命名法
6.要学习相应的代码编辑器的一些常用快捷键，如：快速对齐等等