21. What is the correct option with regards to below snippet?
    

    interface NewCustomer 
    {
    }
    class RegCustomer implements NewCustomer 
    {
    }
    class QuickCustomer implements NewCustomer 
    {
    }
    

1. 1. QuickCustomer can be replaced with RegCustomer

   
   
   

   2. We can instantiate objects of NewCustomer

   
   
   

   3. NewCustomer can be replaced with RegCustomer

   
   
   

   4. RegCustomer can be replaced with QuickCustomer

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   According to Liskov substitution principle we can replace NewCustomer with RegCustomer or QuickCustomer without affecting functionality.

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22. Autocloseable was introduced in which Java version?

1. 1. java SE 4

   
   
   

   2. java SE 6

   
   
   

   3. java SE 7

   
   
   

   4. java SE 8

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   Java 7 introduced autocloseable interface.

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23. What is the alternative of using finally to close resource?

1. 1. throw Exception

   
   
   

   2. try block

   
   
   

   3. autocloseable interface to be implemented

   
   
   

   4. catch block

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   Autocloseable interface provides close() method to close this resource and any other underlying resources.

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24. Which of the below is a child interface of Autocloseable?

1. 1. Auto

   
   
   

   2. Cloneable

   
   
   

   3. Closeable

   
   
   

   4. Close

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   A closeable interface extends autocloseable interface. A Closeable is a source or destination of data that can be closed.

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25. It is a good practise to not throw which exception in close() method of autocloseable?

1. 1. InterruptedException

   
   
   

   2. IOException

   
   
   

   3. CloseException

   
   
   

   4. CustomException

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   InterruptedException interacts with a thread’s interrupted status and runtime misbehavior is likely to occur if an InterruptedException is suppressed.

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