What is numeric promotion?

Java Interview Questions and Answers (part 2)

(Continued from previous question...)

340. 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.

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Other Interview Questions

• Which java.util classes and interfaces support event handling?
• Is sizeof a keyword?
• What are wrapper classes?
• Does garbage collection guarantee that a program will not run out of memory?
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• What is the difference between preemptive scheduling and time slicing?
• Name three Component subclasses that support painting.
• What value does readLine() return when it has reached the end of a file?
• What is the immediate superclass of the Dialog class?
• What is clipping?
• What is a native method?
• Can a for statement loop indefinitely?
• What are order of precedence and associativity, and how are they used?
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• To what value is a variable of the String type automatically initialized?
• What is the catch or declare rule for method declarations?
• What is the difference between a MenuItem and a CheckboxMenuItem?
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• What class is the top of the AWT event hierarchy?
• When a thread is created and started, what is its initial state?
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• What is the range of the short type?
• What is the range of the char type?
• In which package are most of the AWT events that support the event-delegation model defined?
• What is the immediate superclass of Menu?
• What is the purpose of finalization?
• Which class is the immediate superclass of the MenuComponent class.
• What invokes a thread's run() method?
• What is the difference between the Boolean & operator and the && operator?
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• What is the GregorianCalendar class?
• Which Container method is used to cause a container to be laid out and redisplayed?
• What is the purpose of the Runtime class?
• How many times may an object's finalize() method be invoked by the garbage collector?
• What is the purpose of the finally clause of a try-catch-finally statement? garbage collector?
• What is the argument type of a program's main() method?
• Which Java operator is right associative?
• What is the Locale class?
• Can a double value be cast to a byte?
• What is the difference between a break statement and a continue statement?
• What must a class do to implement an interface?
• What method is invoked to cause an object to begin executing as a separate thread?
• Name two subclasses of the TextComponent class.
• What is the advantage of the event-delegation model over the earlier event-inheritance model?
• Which containers may have a MenuBar?
• How are commas used in the initialization and iteration parts of a for statement?
• What is the purpose of the wait(), notify(), and notifyAll() methods?
• What is an abstract method?
• How are Java source code files named?
• What is the relationship between the Canvas class and the Graphics class?
• What are the high-level thread states?
• What value does read() return when it has reached the end of a file?
• Can a Byte object be cast to a double value?
• What is the difference between a static and a non-static inner class?
• What is the difference between the String and StringBuffer classes?
• If a variable is declared as private, where may the variable be accessed?
• What is an object's lock and which objects have locks?
• What is the Dictionary class?
• How are the elements of a BorderLayout organized?
• What is the % operator?
• When can an object reference be cast to an interface reference?
• What is the difference between a Window and a Frame?
• Which class is extended by all other classes?
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• How is rounding performed under integer division?
• What happens when a thread cannot acquire a lock on an object?
• What is the difference between the Reader/Writer class hierarchy and the InputStream/OutputStream class hierarchy?
• What classes of exceptions may be caught by a catch clause?
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• What is the SimpleTimeZone class?
• What is the Map interface?
• Does a class inherit the constructors of its superclass?
• For which statements does it make sense to use a label?
• What is the purpose of the System class?
• Which TextComponent method is used to set a TextComponent to the read-only state?
• How are the elements of a CardLayout organized?
• Is &&= a valid Java operator?
• Name the eight primitive Java types.
• Which class should you use to obtain design information about an object?
• What is the relationship between clipping and repainting?
• Is "abc" a primitive value?
• What is the relationship between an event-listener interface and an event-adapter class?
• What restrictions are placed on the values of each case of a switch statement?
• What modifiers may be used with an interface declaration?
• Is a class a subclass of itself?
• What is the highest-level event class of the event-delegation model?
• What event results from the clicking of a button?
• How can a GUI component handle its own events?
• What is the difference between a while statement and a do statement?
• How are the elements of a GridBagLayout organized?
• What advantage do Java's layout managers provide over traditional windowing systems?
• What is the Collection interface?
• What modifiers can be used with a local inner class?
• What is the difference between static and non-static variables?
• What is the difference between the paint() and repaint() methods?
• What is the purpose of the File class?
• Can an exception be rethrown?
• Which Math method is used to calculate the absolute value of a number?
• How does multithreading take place on a computer with a single CPU?
• When does the compiler supply a default constructor for a class?
• When is the finally clause of a try-catch-finally statement executed?
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• If a method is declared as protected, where may the method be accessed?
• How can the Checkbox class be used to create a radio button?
• Which non-Unicode letter characters may be used as the first character of an identifier?
• What restrictions are placed on method overloading?
• What happens when you invoke a thread's interrupt method while it is sleeping or waiting?
• What is casting?
• What is the return type of a program's main() method?
• Name four Container classes.
• What is the difference between a Choice and a List?
• What class of exceptions are generated by the Java run-time system?
• What class allows you to read objects directly from a stream?
• What is the difference between a field variable and a local variable?
• Under what conditions is an object's finalize() method invoked by the garbage collector?
• How are this () and super () used with constructors?
• What is the relationship between a method's throws clause and the exceptions that can be thrown during the method's execution?
• What is the difference between the JDK 1.02 event model and the event-delegation model introduced with JDK 1.1?
• How is it possible for two String objects with identical values not to be equal under the == operator?
• Why are the methods of the Math class static?
• What Checkbox method allows you to tell if a Checkbox is checked?
• What state is a thread in when it is executing?
• What are the legal operands of the instanceof operator?
• How are the elements of a GridLayout organized?
• What an I/O filter?
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• What is the Set interface?
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• What are E and PI?
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• What is a void return type?
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• What is the purpose of garbage collection?
• What is a compilation unit?
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