Java Core Java - Technical Questions and Answers

61.	What value does read() return when it has reached the end of a file?
	Answer: The read() method returns -1 when it has reached the end of a file. Workspace Report errors ... Name : Email: View Answer

62.	Can a Byte object be cast to a double value?
	Answer: No, an object cannot be cast to a primitive value. Workspace Report errors ... Name : Email: View Answer

63.	What is the difference between a static and a non-static inner class?
	Answer: 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. Workspace Report errors ... Name : Email: View Answer

64.	What is an object's lock and which object's have locks?
	Answer: An object's lock is a mechanism that is used by multiple threads to obtain synchronized access to the object. A thread may execute a synchronized method of an object only after it has acquired the object's lock. All objects and classes have locks. A class's lock is acquired on the class's Class object. Workspace Report errors ... Name : Email: View Answer

65.	What is the % operator?
	Answer: It is referred to as the modulo or remainder operator. It returns the remainder of dividing the first operand by the second operand. Workspace Report errors ... Name : Email: View Answer

66.	When can an object reference be cast to an interface reference?
	Answer: An object reference be cast to an interface reference when the object implements the referenced interface. Workspace Report errors ... Name : Email: View Answer

67.	Which class is extended by all other classes?
	Answer: The Object class is extended by all other classes. Workspace Report errors ... Name : Email: View Answer

68.	Which non-Unicode letter characters may be used as the first character of an identifier?
	Answer: The non-Unicode letter characters $ and _ may appear as the first character of an identifier Workspace Report errors ... Name : Email: View Answer

69.	What restrictions are placed on method overloading?
	Answer: Two methods may not have the same name and argument list but different return types. Workspace Report errors ... Name : Email: View Answer

70.

What is casting?