Answer: collection interface and class : Questions « Utility Classes « SCJP

A, D, E. 

TreeMap is a class that implements the SortedMap interface. 

AbstractList is an abstract class that implements the List interface. 

Collections is a utility class.

8.34.Questions
	8.34.1.	A Hashtable requires String objects as keys(True/False).
	8.34.2.	Answer: hash table key
	8.34.3.	A Hashtable maintains object references in the order they were added(True/False).
	8.34.4.	Answer: hash table value reference
	8.34.5.	Both Vector and Hashtable use synchronized methods to avoid concurrent problems(True/False).
	8.34.6.	Answer: synchronization Vector and Hashtable
	8.34.7.	Which of the following are interfaces? [Check all correct answers]
	8.34.8.	Answer: collection interface and class
	8.34.9.	Which class is most similar to the Vector class?
	8.34.10.	Answer: Vector like collections
	8.34.11.	Which interface does Hashtable implement?
	8.34.12.	Answer: interface for Hashtable
	8.34.13.	Which of the following layout managers can be used to display nine Button objects at one time?
	8.34.14.	Answer: layout
	8.34.15.	Which of the following are valid alignment parameters for a FlowLayout?
	8.34.16.	Answer: flow layout
	8.34.17.	Which of the following layout managers does not alter the height of a component?
	8.34.18.	Answer: layout and component height
	8.34.19.	For JPanel(new GridLayout(4,4,5,8)), the horizontal space between the buttons will be five pixels(True/False).
	8.34.20.	Answer: GridLayout
	8.34.21.	For GridLayout, the order in which the Button objects are added controls their position, filling a row first, from left to right (True/False).
	8.34.22.	Answer: GridLayout(3)
	8.34.23.	Which variable in the GridBagConstraints class can use the constant named CENTER?
	8.34.24.	Answer: GridBagConstraints
	8.34.25.	Which layout manager ensure that at least a portion of each button added is displayed even when the Panel has been resized to a small size?
	8.34.26.	Answer: layout manager
	8.34.27.	Which constant names are valid positioning options in the GridBagConstraints class?
	8.34.28.	Answer: using GridBagConstraints
	8.34.29.	Which of the following classes produce immutable objects?
	8.34.30.	Answer: immutable objects
	8.34.31.	What is the result(autoboxing and parameter passing)?
	8.34.32.	Answer: autoboxing and parameter passing
	8.34.33.	What happens when you compile and run code containing the following lines?
	8.34.34.	Answer: autoboxing and calculation
	8.34.35.	What is the output(substring and file extension name)?
	8.34.36.	Answer: substring and file extension name
	8.34.37.	What is the result(String reference)?
	8.34.38.	Answer: String reference