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91) | Why are the methods of the Math class static? |
| So they can be invoked as if they are a mathematical code library.
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92) | What Checkbox method allows you to tell if a Checkbox is checked? |
| getState
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93) | What state is a thread in when it is executing? |
| An executing thread is in the running state.
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94) | What are the legal operands of the instanceof operator? |
| The left operand is an object reference or null value and the right operand is a class, interface, or array type. |
95) | How are the elements of a GridLayout organized? |
| The elements of a GridBad layout are of equal size and are laid out using the squares of a grid. |
96) | What an I/O filter? |
| An I/O filter is an object that reads from one stream and writes to another, usually altering the data in some way as it is passed from one stream to another. |
97) | If an object is garbage collected, can it become reachable again? |
| Once an object is garbage collected, it ceases to exist. It can no longer become reachable again.
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98) | What is the Set interface? |
| The Set interface provides methods for accessing the elements of a finite mathematical set. Sets do not allow duplicate elements.
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99) | What classes of exceptions may be thrown by a throw statement? |
| A throw statement may throw any expression that may be assigned to the Throwable type.
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100) | What is the purpose of the enableEvents method? |
| The enableEvents method is used to enable an event for a particular object. Normally, an event is enabled when a listener is added to an object for a particular event. The enableEvents method is used by objects that handle events by overriding their event-dispatch methods.
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101) | What is the difference between the File and RandomAccessFile classes? |
| The File class encapsulates the files and directories of the local file system. The RandomAccessFile class provides the methods needed to directly access data contained in any part of a file. |
102) | The File class encapsulates the files and directories of the local file system. The RandomAccessFile class provides the methods needed to directly access data contained in any part of a file. |
| The result is a String object.
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103) | What is your platform's default character encoding? |
| If you are running Java on English Windows platforms, it is probably Cp1252. If you are running Java on English Solaris platforms, it is most likely 8859_1.. |
104) | Which package is always imported by default? |
| The java.lang package is always imported by default. |
105) | What interface must an object implement before it can be written to a stream as an object? |
| An object must implement the Serializable or Externalizable interface before it can be written to a stream as an object. |
106) | How are this and super used? |
| This is used to refer to the current object instance. super is used to refer to the variables and methods of the superclass of the current object instance. |
107) | What is the purpose of garbage collection? |
| The purpose of garbage collection is to identify and discard objects that are no longer needed by a program so that their resources may be reclaimed and reused. |
108) | What is a compilation unit? |
| A compilation unit is a Java source code file. |
109) | What interface is extended by AWT event listeners? |
| All AWT event listeners extend the java.util.EventListener interface. |
110) | What restrictions are placed on method overriding? |
| Overridden methods must have the same name, argument list, and return type.
The overriding method may not limit the access of the method it overrides.
The overriding method may not throw any exceptions that may not be thrown
by the overridden method.
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111) | How can a dead thread be restarted? |
| A dead thread cannot be restarted.
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112) | What happens if an exception is not caught? |
| An uncaught exception results in the uncaughtException method of the thread's ThreadGroup being invoked, which eventually results in the termination of the program in which it is thrown.
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113) | What is a layout manager? |
| A layout manager is an object that is used to organize components in a container. |
114) | Which arithmetic operations can result in the throwing of an ArithmeticException? |
| Integer / and % can result in the throwing of an ArithmeticException.
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115) | What are three ways in which a thread can enter the waiting state? |
| 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 method. |
116) | Can an abstract class be final? |
| An abstract class may not be declared as final. |
117) | What is the ResourceBundle class? |
| 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 run. |
118) | 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? |
| The exception propagates up to the next higher level try-catch statement if any or results in the program's termination.
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119) | What is numeric promotion? |
| 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 required. |
120) | What is the difference between a Scrollbar and a ScrollPane? |
| A Scrollbar is a Component, but not a Container. A ScrollPane is a Container. A ScrollPane handles its own events and performs its own scrolling.
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