Tag: programming languages

Questions Related to programming languages

Which type of driver provides JDBC access via one or more ODBC drivers?
technology programming languages

  1. Type 4 driver

  2. Type 3 driver

  3. Type 2 driver

  4. Type 1 driver

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Correct Option: D

Given: 1. package sun.scjp; 2. public enum Color { RED, GREEN, BLUE } 1. package sun.beta; 2. // insert code here 3. public class Beta { 4. Color g = GREEN; 5. public static void main( String[] argv) 6. { System.out.println( GREEN); } 7. } The class Beta and the enum Color are in different packages. Which two code fragments, inserted individually at line 2 of the Beta declaration, will allow this code to compile? (Choose two.)
technology programming languages

  1. import sun.scjp.Color.*;

  2. import static sun.scjp.Color.*;

  3. import sun.scjp.Color; import static sun.scjp.Color.*;

  4. import sun.scjp.; import static sun.scjp.Color.;

  5. import sun.scjp.Color; import static sun.scjp.Color.GREEN;

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Correct Option: C,E

Given: 11. public static void parse(String str) { 12. try { 13. float f= Float.parseFloat(str); 14. } catch (NumberFormatException nfe) { 15. f= 0; 16. } finally { 17. System.out.println(f); 18. } 19. } 20. public static void main(String[] args) { 21. parse(”invalid”); 22. } What is the result?
technology programming languages

  1. 0.0

  2. Compilation fails

  3. A ParseException is thrown by the parse method at runtime.

  4. A NumberFormatException is thrown by the parse method at

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Correct Option: B

Which type of Statement can execute parameterized queries?
technology programming languages

  1. PreparedStatement

  2. ParameterizedStatement

  3. ParameterizedStatement and CallableStatement

  4. All kinds of Statements (i.e. which implement a sub interface of Statement)

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Correct Option: B

Given: 11. public static void main(String[] args) { 12. Object obj =new int[] { 1,2,3 }; 13. int[] someArray = (int[])obj; 14. for (int i: someArray) System.out.print(i +“ “) 15. } ‘What is the result?
technology programming languages

  1. 1 2 3

  2. B. Compilation fails because of an error in line 12.

  3. B. Compilation fails because of an error in line 13.

  4. B. Compilation fails because of an error in line 14.

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Correct Option: A

Given: 12. public class Test { 13. public enum Dogs {collie, harrier}; 14. public static void main(String [] args) { 15. Dogs myDog = Dogs.collie; 16. switch (myDog) { 17. case collie: 18. System.out.print(”collie “); 19. case harrier: 20. System.out.print(”harrier “); 21. } 22. } 23. } What is the result?
technology programming languages

  1. collie

  2. harrier

  3. Compilation fails

  4. collie harrier

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Correct Option: D

Given: 33. try { 34. // some code here 35. } catch (NullPointerException e1) { 36. System.out.print(”a”); 37. } catch (RuntimeException e2) { 38. System.out.print(”b”); 39. } finally { 40. System.out.print(”c”); 41. } What is the result if a NullPointerException occurs on line 34?
technology programming languages

  1. c

  2. a

  3. ab

  4. ac

  5. bc

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Correct Option: D

Given: 10. public class Foo implements java.io.Serializable { 11. private int x; 12. public int getX() { return x; } 12.publicFoo(int x){this.x=x; } 13. private void writeObject( ObjectOutputStream s) 14. throws IOException { 15. // insert code here 16. } 17. } Which code fragment, inserted at line 15, will allow Foo objects to be correctly serialized and deserialized?
technology programming languages

  1. s.writeInt(x);

  2. s.serialize(x);

  3. s.writeObject(x);

  4. s.defaultWriteObject();

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Correct Option: D
Explanation:

To solve this question, the user needs to understand the concept of serialization in Java. Serialization is the process of converting a Java object into a stream of bytes so that it can be stored in a file or transmitted over a network. Deserialization is the reverse process of converting a stream of bytes back into a Java object.

The code given above defines a class Foo that implements the Serializable interface. This means that instances of Foo can be serialized and deserialized. The writeObject() method is a callback method that is called during serialization and allows the developer to customize the serialization process.

Option A: s.writeInt(x); This option will write the integer value of x to the ObjectOutputStream. However, this is not enough to fully serialize the Foo object, as there are other instance variables besides x that also need to be serialized.

Option B: s.serialize(x); This option is not valid, as there is no such method as serialize() in the ObjectOutputStream class.

Option C: s.writeObject(x); This option will write the object x to the ObjectOutputStream. However, this will not fully serialize the Foo object, as x is just one instance variable and there are others that also need to be serialized.

Option D: s.defaultWriteObject(); This option is the correct answer. The defaultWriteObject() method serializes all non-transient, non-static instance variables in the object. This includes the instance variable x, as well as any other instance variables that Foo may have. By calling this method, we ensure that the entire Foo object is serialized and can be correctly deserialized later.

Therefore, the answer is: D

Given: 11. String test= “a1b2c3”; 12. String[] tokens = test.split(”\d”); 13. for(String s: tokens) System.out.print(s +“ “); What is the result?
technology programming languages

  1. a b c

  2. 1 2 3

  3. a1b2c3

  4. Compilation fails

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Correct Option: A

Which two are true? (Choose two.)
technology programming languages

  1. An encapsulated, public class promotes re-use.

  2. Classes that share the same interface are always tightly

  3. An encapsulated class allows subclasses to overload methods, but

  4. An encapsulated class allows a programmer to change an

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Correct Option: A,D