61. What is the
argument type of a program's main() method?
A program's
main() method takes an argument of the String[] type.
62. Which Java
operator is right associative?
The = operator is
right associative.
63. What is the
Locale class?
The Locale class
is used to tailor program output to the conventions of a particular geographic,
political, or cultural region.
64. Can a double
value be cast to a byte?
Yes, a double
value can be cast to a byte.
65. What is the
difference between a break statement and a continue statement?
A break statement
results in the termination of the statement to which it applies (switch, for,
do, or while). A continue statement is used to end the current loop iteration
and return control to the loop statement.
66. What must a
class do to implement an interface?
It must provide
all of the methods in the interface and identify the interface in its
implements clause.
67. What method
is invoked to cause an object to begin executing as a separate thread?
The start()
method of the Thread class is invoked to cause an object to begin executing as
a separate thread.
68. Name two
subclasses of the TextComponent class.
TextField and
TextArea
69. What is the
advantage of the event-delegation model over the earlier event-inheritance
model?
The
event-delegation model has two advantages over the event-inheritance model.
First, it enables event handling to be handled by objects other than the ones
that generate the events (or their containers). This allows a clean separation
between a component's design and its use. The other advantage of the
event-delegation model is that it performs much better in applications where
many events are generated. This performance improvement is due to the fact that
the event-delegation model does not have to repeatedly process unhandled
events, as is the case of the event-inheritance model.
70. Which
containers may have a MenuBar?
Frame
71. How are
commas used in the intialization and iteration parts of a for statement?
Commas are used
to separate multiple statements within the initialization and iteration parts
of a for statement.
72. What is the
purpose of the wait(), notify(), and notifyAll() methods?
The
wait(),notify(), and notifyAll() methods are used to provide an efficient way
for threads to wait for a shared resource. When a thread executes an object's
wait() method, it enters the waiting state. It only enters the ready state
after another thread invokes the object's notify() or notifyAll() methods..
73. What is an
abstract method?
An abstract
method is a method whose implementation is deferred to a subclass.
74. How are Java
source code files named?
A Java source
code file takes the name of a public class or interface that is defined within
the file. A source code file may contain at most one public class or interface.
If a public class or interface is defined within a source code file, then the
source code file must take the name of the public class or interface. If no
public class or interface is defined within a source code file, then the file
must take on a name that is different than its classes and interfaces. Source
code files use the .java extension.
75. What is the
relationship between the Canvas class and the Graphics class?
A Canvas object
provides access to a Graphics object via its paint() method.
76. What are the
high-level thread states?
The high-level
thread states are ready, running, waiting, and dead.
77. What value
does read() return when it has reached the end of a file?
The read() method
returns -1 when it has reached the end of a file.
78. Can a Byte
object be cast to a double value?
No, an object
cannot be cast to a primitive value.
79. What is the
difference between a static and a non-static inner class?
A non-static
inner class may have object instances that are associated with instances of the
class's outer class. A static inner class does not have any object instances.
80. What is the
difference between the String and StringBuffer classes?
String objects are constants. StringBuffer
objects are not.
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