Java Java Basics - Technical Questions and Answers

91.	How many objects are created in the following piece of code? MyClass c1, c2, c3; c1 = new MyClass (); c3 = new MyClass ();
	Answer: Only 2 objects are created, c1 and c3. The reference c2 is only declared and not initialized. Workspace Report errors ... Name : Email: View Answer

92.	Can a public class MyClass be defined in a source file named YourClass.java?
	Answer: No. The source file name, if it contains a public class, must be the same as the public class name itself with a .java extension. Workspace Report errors ... Name : Email: View Answer

93.	Can main() method be declared final?
	Answer: Yes, the main() method can be declared final, in addition to being public static. Workspace Report errors ... Name : Email: View Answer

94.	What is HashMap and Map?
	Answer: Map is an Interface and Hashmap is the class that implements Map. Workspace Report errors ... Name : Email: View Answer

95.	Difference between HashMap and HashTable?
	Answer: The HashMap class is roughly equivalent to Hashtable, except that it is unsynchronized and permits nulls. (HashMap allows null values as key and value whereas Hashtable doesnt allow). HashMap does not guarantee that the order of the map will remain constant over time. HashMap is unsynchronized and Hashtable is synchronized. Workspace Report errors ... Name : Email: View Answer

96.	Difference between Vector and ArrayList?
	Answer: Vector is synchronized whereas arraylist is not. Workspace Report errors ... Name : Email: View Answer

97.	Difference between Swing and Awt?
	Answer: AWT are heavy-weight componenets. Swings are light-weight components. Hence swing works faster than AWT. Workspace Report errors ... Name : Email: View Answer

98.

What will be the default values of all the elements of an array defined as an instance variable?

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