This page discusses - Core Java Interview Question, Interview QuestionThis page discusses - Core Java Interview Question, Interview Question
Question: How are the elements of a GridLayout organized?
Answer: The elements of a GridBad layout are of equal size and are laid out using the squares of a grid.
Question: What an I/O filter?
Answer: 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.
Question: If an object is garbage collected, can it become reachable again?
Answer: Once an object is garbage collected, it ceases to exist.It can no longer become reachable again.
Question: What is the Set interface?
Answer: The Set interface provides methods for accessing the elements of a finite mathematical set. Sets do not allow duplicate elements.
Question: What classes of exceptions may be thrown by a throw statement?
Answer: A throw statement may throw any expression that may be assigned to the Throwable type.
Question: What are E and PI?
Answer: E is the base of the natural logarithm and PI is mathematical value pi.
Question: Are true and false keywords?
Answer: The values true and false are not keywords.
Question: What is a void return type?
Answer: A void return type indicates that a method does not return a value.
Question: What is the purpose of the enableEvents() method?
Answer: 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.
Question: What is the difference between the File and RandomAccessFile classes?
Answer: 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.
Question: What happens when you add a double value to a String?
Answer: The result is a String object.
Question: What is your platform's default character encoding?
Answer: 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..
Question: Which package is always imported by default?
Answer: The java.lang package is always imported by default.
Question: What interface must an object implement before it can be written to a stream as an object?
Answer: An object must implement the Serializable or Externalizable interface before it can be written to a stream as an object.
Question: How are this and super used?
Answer: 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.
Question: What is the purpose of garbage collection?
Answer: 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.