Java Core Java - Technical Questions and Answers

101.	Can an abstract class be final?
	Answer: An abstract class may not be declared as final. Workspace Report errors ... Name : Email: View Answer

102.

What is numeric promotion?

103.	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 package. Workspace Report errors ... Name : Email: View Answer

104.	To what value is a variable of the boolean type automatically initialized?
	Answer: The default value of the boolean type is false. Workspace Report errors ... Name : Email: View Answer

105.	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 value. Workspace Report errors ... Name : Email: View Answer

106.	What restrictions are placed on method overriding?
	Answer: 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. Workspace Report errors ... Name : Email: View Answer

107.	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 interfaces. Workspace Report errors ... Name : Email: View Answer

108.	What modifiers may be used with a top-level class?
	Answer: A top-level class may be public, abstract, or final. Workspace Report errors ... Name : Email: View Answer

109.	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 executed. Workspace Report errors ... Name : Email: View Answer

110.

What are the practical benefits, if any, of importing a specific class rather than an entire package (e.g. import java.net.* versus import java.net.Socket)?