java枚舉類型

//Book.java

public enum Book {
	
	//declare constants of enum type
	JHTP("Java How to Program", "2012"),
	CHTP("C How to Program", "2007"),
	CPPHTP("C++ How to Program", "2012");
	
	//instance fields
	private final String title;
	private final String copyrightYear;
	
	//enum constructor
	Book(String bookTitle, String year)
	{
		title = bookTitle;
		copyrightYear = year;
		
	}
	public String getTitle()
	{
		return title;
	}
	public String getCopyrightYear()
	{
		return copyrightYear;
	}
}

//EnumTest.java

class EnumTest {

	public static void main(String[] args)
	{
		System.out.println("All books:\n");
		
		for(Book book : Book.values())
		{
			System.out.printf("%-10s%-45s%s\n", 
					book, book.getTitle(), book.getCopyrightYear());
		}

	}
}