Applied

• Use the GregorianCalendar, Calendar, Date, and DateFormat classes to get the current date, to set dates, to calculate elapsed days, and to format dates.
• Use the methods of the String class to manipulate and compare strings.
• Use the StringBuilder class to create a mutable string, and use the methods of a StringBuilder object to work with the string.
• Given Java code that uses any of the language elements presented in this chapter, explain what each statement does.

Knowledge

• Describe the difference between how dates are stored in GregorianCalendar and Date objects.
• Describe two situations where you would typically use Date objects rather than GregorianCalendar objects.
• Explain the difference between a mutable and an immutable string and why it's usually more efficient to use a mutable string.
• Explain how Java determines the initial capacity of a StringBuilder object and the new capacity of a StringBuilder object when its current capacity is exceeded.