INTERVIEW QUESTIONS
1. What is a transient
variable?
2. Which containers use a
border Layout as their default layout?
3. Why do threads block
on I/O?
4. How are Observer and
Observable used?
5. What is
synchronization and why is it important?
6. Can a lock be acquired
on a class?
7. What's new with the
stop(), suspend() and resume() methods in JDK 1.2?
8. Is null a keyword?
9. What is the preferred
size of a component?
10. What method is used
to specify a container's layout?
11. Which containers use
a FlowLayout as their default layout?
12. What state does a
thread enter when it terminates its processing?
13. What is the
Collections API?
14. Which characters may
be used as the second character of an identifier, but not as the first
character of an
identifier?
15.
What is the List interface?
16. How does Java handle
integer overflows and underflows?
17. What is the Vector
class?
18. What modifiers may be
used with an inner class that is a member of an outer class?
19. What is an Iterator
interface?
20. What is the
difference between the >> and >>> operators?
21. Which method of the
Component class is used to set the position and size of a component?
22. How many bits are
used to represent Unicode, ASCII, UTF-16, and UTF-8 characters?
23What is the difference
between yielding and sleeping?
24. Which java.util
classes and interfaces support event handling?
25. Is sizeof a keyword?
26. What are wrapped
classes?
27. Does garbage
collection guarantee that a program will not run out of memory?
28. What restrictions are
placed on the location of a package statement within a source code file?
29. Can an object's
finalize() method be invoked while it is reachable?
30. What is the immediate
superclass of the Applet class?
31.
What is the difference between preemptive scheduling and time slicing?
32.
Name three Component subclasses that support painting.
33. What value does
readLine() return when it has reached the end of a file?
34. What is the immediate
superclass of the Dialog class?
35. What is clipping?
36. What is a native
method?
37. Can a for statement
loop indefinitely?
38. What are order of
precedence and associativity, and how are they used?
39. When a thread blocks
on I/O, what state does it enter?
40. To what value is a
variable of the String type automatically initialized?
41. What is the catch or
declare rule for method declarations?
42. What is the
difference between a MenuItem and a CheckboxMenuItem?
43. What is a task's
priority and how is it used in scheduling?
44. What class is the top
of the AWT event hierarchy?
45. When a thread is
created and started, what is its initial state?
46. Can an anonymous
class be declared as implementing an interface and extending a class?
47. What is the range of
the short type?
48. What is the range of
the char type?
49. In which package are
most of the AWT events that support the event-delegation model defined?
50. What is the immediate
superclass of Menu?
51. What is the purpose
of finalization?
52. Which class is the
immediate superclass of the MenuComponent class.
53. What invokes a
thread's run() method?
54. What is the
difference between the Boolean & operator and the && operator?
55. Name three subclasses
of the Component class.
56. What is the
GregorianCalendar class?
57. Which Container
method is used to cause a container to be laid out and redisplayed?
58. What is the purpose
of the Runtime class?
59. How many times may an
object's finalize() method be invoked by the garbage collector?
60. What is the purpose
of the finally clause of a try-catch-finally statement?
61. What is the argument
type of a program's main() method?
62. Which Java operator
is right associative?
63. What is the Locale
class?
64. Can a double value be
cast to a byte?
65. What is the
difference between a break statement and a continue statement?
66. What must a class do
to implement an interface?
67. What method is
invoked to cause an object to begin executing as a separate thread?
68. Name two subclasses
of the TextComponent class.
69. What is the advantage
of the event-delegation model over the earlier event-inheritance model?
70. Which containers may
have a MenuBar?
71. How are commas used
in the initialization and iteration parts of a for statement?
72. What is the purpose
of the wait(), notify(), and notifyAll() methods?
73. What is an abstract
method?
74. How are Java source
code files named?
75. What is the
relationship between the Canvas class and the Graphics class?
76. What are the
high-level thread states?
77. What value does
read() return when it has reached the end of a file?
78. Can a Byte object be
cast to a double value?
79. What is the
difference between a static and a non-static inner class?
80. What is the
difference between the String and StringBuffer classes?
81. If a variable is
declared as private, where may the variable be accessed?
82. What is an object's
lock and which object's have locks?
83. What is the
Dictionary class?
84. How are the elements
of a BorderLayout organized?
85. What is the %
operator?
86. When can an object
reference be cast to an interface reference?
87. What is the
difference between a Window and a Frame?
88. Which class is
extended by all other classes?
89. Can an object be
garbage collected while it is still reachable?
90. Is the ternary
operator written x : y ? z or x ? y : z ?
91. What is the
difference between the Font and FontMetrics classes?
92. How is rounding
performed under integer division?
93. What happens when a
thread cannot acquire a lock on an object?
94. What is the
difference between the Reader/Writer class hierarchy and the InputStream/
OutputStream class
hierarchy?
95. What classes of
exceptions may be caught by a catch clause?
96. If a class is
declared without any access modifiers, where may the class be accessed?
97. What is the
SimpleTimeZone class?
98. What is the Map interface?
99. Does a class inherit
the constructors of its superclass?
100. For which statements
does it make sense to use a label?
101. What is the purpose
of the System class?
102. Which TextComponent
method is used to set a TextComponent to the read-only state?
103. How are the elements
of a CardLayout organized?
104. Is &&= a
valid Java operator?
105. Name the eight
primitive Java types.
106. Which class should
you use to obtain design information about an object?
107. What is the
relationship between clipping and repainting?
108. Is "abc" a
primitive value?
109. What is the
relationship between an event-listener interface and an event-adapter class?
110. What restrictions
are placed on the values of each case of a switch statement?
111. What modifiers may be
used with an interface declaration?
112. Is a class a
subclass of itself?
113. What is the
highest-level event class of the event-delegation model?
114. What event results
from the clicking of a button?
115. How can a GUI
component handle its own events?
116. What is the
difference between a while statement and a do statement?
117. How are the elements
of a GridBagLayout organized?
118. What advantage do
Java's layout managers provide over traditional windowing systems?
119. What is the
Collection interface?
120. What modifiers can
be used with a local inner class?
121. What is the
difference between static and non-static variables?
122. What is the
difference between the paint() and repaint() methods?
123. What is the purpose
of the File class?
124. Can an exception be
rethrown?
125. Which Math method is
used to calculate the absolute value of a number?
126. How does
multithreading take place on a computer with a single CPU?
127. When does the
compiler supply a default constructor for a class?
128. When is the finally
clause of a try-catch-finally statement executed?
129. Which class is the
immediate superclass of the Container class?
130. If a method is
declared as protected, where may the method be accessed?
131. How can the Checkbox
class be used to create a radio button?
132. Which non-Unicode
letter characters may be used as the first character of an identifier?
133. What restrictions
are placed on method overloading?
134. What happens when
you invoke a thread's interrupt method while it is sleeping or waiting?
135. What is casting?
136. What is the return
type of a program's main() method?
137. Name four Container
classes.
138. What is the
difference between a Choice and a List?
139. What class of
exceptions are generated by the Java run-time system?
140. What class allows
you to read objects directly from a stream?
141. What is the
difference between a field variable and a local variable?
142. Under what
conditions is an object's finalize() method invoked by the garbage collector?
143. How are this() and
super() used with constructors?
144. What is the
relationship between a method's throws clause and the exceptions that can be thrown
during the method's execution?
145. What is the
difference between the JDK 1.02 event model and the event-delegation model introduced
with JDK 1.1?
146. How is it possible
for two String objects with identical values not to be equal under the == operator?
147. Why are the methods
of the Math class static?
148. What Checkbox method
allows you to tell if a Checkbox is checked?
149. What state is a
thread in when it is executing?
150. What are the legal
operands of the instanceof operator?
151. How are the elements
of a GridLayout organized?
152. What an I/O filter?
153. If an object is
garbage collected, can it become reachable again?
154. What is the Set
interface?
155. What classes of
exceptions may be thrown by a throw statement?
156. What are E and PI?
157. Are true and false
keywords?
158. What is a void
return type?
159. What is the purpose
of the enableEvents() method?
160. What is the
difference between the File and RandomAccessFile classes?
161. What happens when
you add a double value to a String?
162. What is your
platform's default character encoding?
163. Which package is
always imported by default?
164. What interface must
an object implement before it can be written to a stream as an object?
165. How are this and
super used?
166. What is the purpose
of garbage collection?
167. What is a
compilation unit?
168. What interface is
extended by AWT event listeners?
169. What restrictions
are placed on method overriding?
170. How can a dead
thread be restarted?
171. What happens if an
exception is not caught?
172. What is a layout
manager?
173. Which arithmetic
operations can result in the throwing of an ArithmeticException?
174. What are three ways
in which a thread can enter the waiting state?
175. Can an abstract
class be final?
176. What is the
ResourceBundle class?
177. What happens if a
try-catch-finally statement does not have a catch clause to handle an
exception that is thrown
within the body of the try statement?
178. What is numeric
promotion?
179. What is the
difference between a Scrollbar and a ScrollPane?
180. What is the
difference between a public and a non-public class?
181. To what value is a
variable of the boolean type automatically initialized?
182. Can try statements
be nested?
183. What is the
difference between the prefix and postfix forms of the ++ operator?
184. What is the purpose
of a statement block?
185. What is a Java
package and how is it used?
186. What modifiers may
be used with a top-level class?
187. What are the Object
and Class classes used for?
188. How does a try
statement determine which catch clause should be used to handle an exception?
189. Can an unreachable
object become reachable again?
190. When is an object
subject to garbage collection?
191. What method must be
implemented by all threads?
192. What methods are
used to get and set the text label displayed by a Button object?
193. Which Component
subclass is used for drawing and painting?
194. What are
synchronized methods and synchronized statements?
195. What are the two
basic ways in which classes that can be run as threads may be defined?
196. What are the
problems faced by Java programmers who don't use layout managers?
197. What is the
difference between an if statement and a switch statement?
198. What is the List
interface?
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