core java multiple choice questions Mcqs practice questions

21. Which keyword can protect a class in a package from accessibility by the classes outside the package?.

A. private 
B. protected 
C. Final 
D. Don`t use any keyword at all (make it default) 

22. What is the error in the following class definitions? abstract class SY{abstract sum(int x, int y) { }}.

A. Class header is not defined properly 
B. Constructor is not defined 
C. Method is not defined properly 
D. no error 

23. What interface must all interfaces for remote services exted?.

A. java.rmi.RemoteService 
B. java.rmi.Remotable 
C. java.rmi.Remote 
D. java.rmi.server.Remote 

24. which statement are true? .

A. the class thrad is abstract 
B. the class thread implements runnable 
C. a program terminates when the last non-daemon thread ends 
D. both 2 and 3 

25. Which of the following methods helps in getting the local host ip?.

A. getLocalHost() 
B. getRemoteHost() 
C. getIpAddress() 
D. getHost() 

26. Which of the Following is not java primitive.

A. Boolean 
B. Long 
C. Float 
D. String 

27. What is the purpose of the main() method?.

A. To hold the APIS of the application 
B. To create the Buttons and scrollabars 
C. To act as entry point for the program 
D. none of the above 

28. getByName() throws ____________ Exception.

A. UnknownHost 
B. illegalAccess 
C. NullPointer 
D. All of the above 

29. clone method is of class.

A. Clonable 
B. Object 
C. Class 
D. None of the above 

30. Which variables can an inner class access from the class which encapsulates it?.

A. All static variables,all final variable ,all instance variable 
B. Only final static variables  
C. Only final instance variables  
D. only public variable 

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