Que- What will be the output of the following Java code snippet? int a = random.nextInt(7) + 4;
a. Random number between 4 to 7, including 4 and 7
b. Random number between 4 to 7, excluding 4 and 7
c. Random number between 4 to 10, excluding 4 and 10
d. Random number between 4 to 10, including 4 and 10
Answer- Random number between 4 to 10, including 4 and 10
Que- Math.random() guarantees uniqueness?
a.TRUE
b.FALSE
c.Nothing Can be Said
d.None of the mentioned
Answer-FALSE
Que- What is the signature of Math.random() method?
a. public static double random()
b. public void double random()
c. public static int random()
d. public void int random()
Answer- public static double random()
Que- Which of these class produce objects with respect to geographical locations?
a. TimeZone
b. Locale
c. Date
d. SimpleTimeZone
Answer- Locale
Que- Which of these class can generate pseudorandom numbers?
a. Locale
b. Rand
c. Random
d. None of the mentioned
Answer- Random
Que- Which of these method of Locale class can be used to obtain country of operation?
a. getCountry()
b. whichCountry()
c. DisplayCountry()
d. getDisplayCountry()
Answer- getDisplayCountry()
Que- Which of these is a method can generate a boolean output?
a. retbool()
b. getBool()
c. nextBool()
d. nextBoolean()
Answer- nextBoolean()
Que- What is the use of Observable class?
a. It is used to create global subclasses
b. It is used to create classes that other part of the program can observe
c. It is used to create classes that can be accessed by other parts of program
d. It is used to create methods that can be accessed by other parts of program
Answer- It is used to create classes that other part of the program can observe
Que- Which of these methods is used to notify observer the change in observed object?
a. update()
b. notify()
c. check()
d. observed()
Answer- update()
Que- Which of these methods calls update() method?
a. notify()
b. observeObject()
c. updateObserver()
d. notifyObserver()
Answer- notifyObserver()
Que- Which of these methods is called when observed object has changed?
a. setChanged()
b. update()
c. notifyObserver()
d. all of the mentioned
Answer- all of the mentioned
Que- Which of these classes can schedule task for execution in future?
a. Thread
b. Timer
c. System
d. Observer
Answer- Timer
Que- Which of these interfaces is implemented by TimerTask class?
a. Runnable
b. Thread
c. Observer
d. ThreadCount
Answer- Runnable
Que- Which of these package provides the ability to read and write in Zip format?
a. java.lang
b. java.io
c. java.util.zip
d. java.util.zar
Answer- java.util.zip
Que- Which of these keywords is used to define packages in Java?
a. pkg
b. Pkg
c. package
d. Package
Answer- package
Que- Which of these is a mechanism for naming and visibility control of a class and its content?
a. Object
b. Packages
c. Interfaces
d. None of the Mentioned.
Answer- Packages
Que- Which of this access specifies can be used for a class so that its members can be accessed by a different class in the same package?
a. Public
b. Protected
c. No Modifier
d. All of the mentioned
Answer- All of the mentioned
Que- Which of these access specifiers can be used for a class so that its members can be accessed by a different class in the different package?
a. Public
b. Protected
c. Private
d. No Modifier
Answer- Public
Que- Which of the following is the correct way of importing an entire package 'pkg'?
a. import pkg.
b. Import pkg.
c. import pkg.*
d. Import pkg.*
Answer- import pkg.*
Que- Which of the following is an incorrect statement about packages?
a. Package defines a namespace in which classes are stored
b. A package can contain other package within it
c. Java uses file system directories to store packages
d. A package can be renamed without renaming the directory in which the classes are stored
Answer- A package can be renamed without renaming the directory in which the classes are stored
Que- Which of the following package stores all the standard java classes?
a. lang
b. java
c. util
d. java.packages
Answer- java
Que- Which of these keywords is used to define interfaces in Java?
a. interface
b. Interface
c. intf
d. Intf
Answer- interface
Que- Which of these can be used to fully abstract a class from its implementation?
a. Objects
b. Packages
c. Interfaces
d. None of the Mentioned
Answer- Interfaces
Que- Which of these access specifiers can be used for an interface?
a. Public
b. Protected
c. private
d. All of the mentioned
Answer- Public
Que- Which of these keywords is used by a class to use an interface defined previously?
a. import
b. Import
c. implements
d. Implements
Answer- implements
Que- Which of the following is the correct way of implementing an interface salary by class manager?
a. class manager extends salary {}
b. class manager implements salary {}
c. class manager imports salary {}
d. none of the mentioned
Answer- class manager implements salary {}
Que- Which of the following is an incorrect statement about packages?
a. Interfaces specifies what class must do but not how it does
b. Interfaces are specified public if they are to be accessed by any code in the program
c. All variables in interface are implicitly final and static
d. All variables are static and methods are public if interface is defined pubic
Answer- All variables are static and methods are public if interface is defined pubic
Que- Which of the following access specifiers can be used for an interface?
a. Protected
b. Private
c. Public
d. Public, protected, private
Answer- Protected
Que- Which of the following is the correct way of implementing an interface A by class B?
a. class B extends A{}
b. class B implements A{}
c. class B imports A{}
d. None of the mentioned
Answer- class B implements A{}
Que- All methods must be implemented of an interface.
a.TRUE
b.FALSE
c.Nothing Can be Said
d.None of the mentioned
Answer-TRUE
Que- What type of variable can be defined in an interface?
a. public static
b. private final
c. public final
d. static final
Answer- static final
Que- What does an interface contain?
a. Method definition
b. Method declaration
c. Method declaration and definition
d. Method name
Answer- Method declaration
Que- What type of methods an interface contain by default?
a. abstract
b. static
c. final
d. private
Answer- abstract
Que- What will happen if we provide concrete implementation of method in interface?
a. The concrete class implementing that method need not provide implementation of that method
b. Runtime exception is thrown
c. Compilation failure
d. Method not found exception is thrown
Answer- Compilation failure
Que- What happens when a constructor is defined for an interface?
a. Compilation failure
b. Runtime Exception
c. The interface compiles successfully
d. The implementing class will throw exception
Answer- Compilation failure
Que- What happens when we access the same variable defined in two interfaces implemented by the same class?
a. Compilation failure
b. Runtime Exception
c. The JVM is not able to identify the correct variable
d. The interfaceName.variableName needs to be defined
Answer- The interfaceName.variableName needs to be defined
Que- Which of these package is used for graphical user interface?
a. java.applet
b. java.awt
c. java.awt.image
d. java.io
Answer- java.awt
Que- Which of this package is used for analyzing code during run-time?
a. java.applet
b. java.awt
c. java.io
d. java.lang.reflect
Answer- java.lang.reflect
Que- Which of this package is used for handling security related issues in a program?
a. java.security
b. java.lang.security
c. java.awt.image
d. java.io.security
Answer- java.security