344.
Question: Which arithmetic operations can result in the throwing of an ArithmeticException?
345. Question: What are three ways in which a thread can enter the waiting state?
346. Question: Can an abstract class be final?
347. Question: What is the ResourceBundle class?
348. Question: 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?
349. Question: What is numeric promotion?
350. Question: What is the difference between a Scrollbar and a ScrollPane?
351. Question: What is the difference between a public and a non-public class?
352. Question: To what value is a variable of the boolean type automatically initialized?
353. Question: Can try statements be nested?
354. Question: What is the difference between the prefix and postfix forms of the ++ operator?
355. Question: What is the purpose of a statement block?
356. Question: What is a Java package and how is it used?
357. Question: What modifiers may be used with a top-level class?
358. Question: What are the Object and Class classes used for?
359. Question: How does a try statement determine which catch clause should be used to handle an exception?
360. Question: Can an unreachable object become reachable again?
361. Question: When is an object subject to garbage collection?
362. Question: What method must be implemented by all threads?
363. Question: What methods are used to get and set the text label displayed by a Button object?
364. Question: Which Component subclass is used for drawing and painting?
365. Question: What are synchronized methods and synchronized statements?
366. Question: What are the two basic ways in which classes that can be run as threads may be defined?
367. Question: What are the problems faced by Java programmers who don't use layout managers?
368. Question: What is the difference between an if statement and a switch statement?
369. Question: What happens when you add a double value to a String?
370. Question: What is the List interface?
371. Question: Why do we need public static void main(String args[]) method in Java
372. Question: What is the difference between an Interface and an Abstract class
373. Question: Explain serialization
374. Question: What are the rules of serialization
375. Question: What is difference between error and exception
Answer :
Integer / and % can result in the throwing of an ArithmeticException345. Question: What are three ways in which a thread can enter the waiting state?
Answer :
A thread can enter the waiting state by invoking its sleep() method, by blocking on I/O, by unsuccessfully attempting to acquire an object's lock, or by invoking an object's wait() method. It can also enter the waiting state by invoking its (deprecated) suspend() method346. Question: Can an abstract class be final?
Answer :
An abstract class may not be declared as final347. Question: What is the ResourceBundle class?
Answer :
The ResourceBundle class is used to store locale-specific resources that can be loaded by a program to tailor the program's appearance to the particular locale in which it is being run348. Question: 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?
Answer :
The exception propagates up to the next higher level try-catch statement (if any) or results in the program's termination349. Question: What is numeric promotion?
Answer :
Numeric promotion is the conversion of a smaller numeric type to a larger numeric type, so that integer and floating-point operations may take place. In numerical promotion, byte, char, and short values are converted to int values. The int values are also converted to long values, if necessary. The long and float values are converted to double values, as required350. Question: What is the difference between a Scrollbar and a ScrollPane?
Answer :
A Scrollbar is a Component, but not a Container. A ScrollPane is a Container. A ScrollPane handles its own events and performs its own scrolling351. Question: What is the difference between a public and a non-public class?
Answer :
A public class may be accessed outside of its package. A non-public class may not be accessed outside of its package352. Question: To what value is a variable of the boolean type automatically initialized?
Answer :
The default value of the boolean type is false353. Question: Can try statements be nested?
Answer :
Try statements may be tested354. Question: What is the difference between the prefix and postfix forms of the ++ operator?
Answer :
The prefix form performs the increment operation and returns the value of the increment operation. The postfix form returns the current value all of the expression and then performs the increment operation on that value355. Question: What is the purpose of a statement block?
Answer :
A statement block is used to organize a sequence of statements as a single statement group356. Question: What is a Java package and how is it used?
Answer :
A Java package is a naming context for classes and interfaces. A package is used to create a separate name space for groups of classes and interfaces. Packages are also used to organize related classes and interfaces into a single API unit and to control accessibility to these classes and interfaces357. Question: What modifiers may be used with a top-level class?
Answer :
A top-level class may be public, abstract, or final358. Question: What are the Object and Class classes used for?
Answer :
The Object class is the highest-level class in the Java class hierarchy. The Class class is used to represent the classes and interfaces that are loaded by a Java program359. Question: How does a try statement determine which catch clause should be used to handle an exception?
Answer :
When an exception is thrown within the body of a try statement, the catch clauses of the try statement are examined in the order in which they appear. The first catch clause that is capable of handling the exception is executed. The remaining catch clauses are ignored360. Question: Can an unreachable object become reachable again?
Answer :
An unreachable object may become reachable again. This can happen when the object's finalize() method is invoked and the object performs an operation which causes it to become accessible to reachable objects361. Question: When is an object subject to garbage collection?
Answer :
An object is subject to garbage collection when it becomes unreachable to the program in which it is used362. Question: What method must be implemented by all threads?
Answer :
All tasks must implement the run() method, whether they are a subclass ofThread or implement the Runnable interface363. Question: What methods are used to get and set the text label displayed by a Button object?
Answer :
getLabel() and setLabel()364. Question: Which Component subclass is used for drawing and painting?
Answer :
Canvas365. Question: What are synchronized methods and synchronized statements?
Answer :
Synchronized methods are methods that are used to control access to an object. A thread only executes a synchronized method after it has acquired the lock for the method's object or class. Synchronized statements are similar to synchronized methods. A synchronized statement can only be executed after a thread has acquired the lock for the object or class referenced in the synchronized statement366. Question: What are the two basic ways in which classes that can be run as threads may be defined?
Answer :
A thread class may be declared as a subclass of Thread, or it may implement the Runnable interface367. Question: What are the problems faced by Java programmers who don't use layout managers?
Answer :
Without layout managers, Java programmers are faced with determining how their GUI will be displayed across multiple windowing systems and finding a common sizingand positioning that will work within the constraints imposed by each windowing system368. Question: What is the difference between an if statement and a switch statement?
Answer :
The if statement is used to select among two alternatives. It uses a boolean expression to decide which alternative should be executed. The switch statement is used to select among multiple alternatives. It uses an int expression to determine which alternative should be executed369. Question: What happens when you add a double value to a String?
Answer :
The result is a String object370. Question: What is the List interface?
Answer :
The List interface provides support for ordered collections of objects371. Question: Why do we need public static void main(String args[]) method in Java
Answer :
We need public: The method can be accessed outside the class / package static: You need not have an instance of the class to access the method void: Your application need not return a value, as the JVM launcher would return the value when it exits main(): This is the entry point for the application If the main() was not static, you would require an instance of the class in order to execute the method. If this is the case, what would create the instance of the class? What if your class did not have a public constructor?372. Question: What is the difference between an Interface and an Abstract class
Answer :
In abstract class you can define as well as declare methods, the methods which are declared are to be marked as abstract In interface all we just declare methods and the definition is provided by the class which is implementing it373. Question: Explain serialization
Answer :
Serialization means storing a state of a java object by coverting it to byte stream374. Question: What are the rules of serialization
Answer :
Rules: 1. Static fileds are not serialized because they are not part of any one particular object 2. Fileds from the base class are handled only if hose are serializable 3. Transient fileds are not serialized375. Question: What is difference between error and exception
Answer :
Error occurs at runtime and cannot be recovered, Outofmemory is one such example. Exceptions on the other hand are due conditions which the application encounters such as FileNotFound exception or IO exceptions
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