Java Programming - 13

LIST OF ATTEMPTED QUESTIONS AND ANSWERS

Multiple Choice Multiple Answer
Question: When might your program wish to run the garbage collector?
Correct Answer: When it knows there will be some idle time , Before it enters a compute-intense section of code , Before it enters a memory-intense section of code
Your Answer: Before it enters a memory-intense section of code , When it knows there will be some idle time , Before objects are finalized

Match The Following
Question Correct Answer Your Answer
start( ) thread main
main thread child thread child thread
NewThread this new
sleep( ) milliseconds milliseconds


Multiple Choice Multiple Answer
Question: Expression must be of the data types :-
Correct Answer: Byte , Short , Int
Your Answer: Byte , Int , Boolean

Multiple Choice Single Answer
Question: What are members of the threads class?
Correct Answer: Method
Your Answer: Method

Multiple Choice Multiple Answer
Question: What modifiers may be used with top-level class?
Correct Answer: Public , Abstract , Final
Your Answer: Public , Abstract , Final

Select The Blank
Question: Start( )executes a call to ________.
Correct Answer: run( )
Your Answer: run( )

Multiple Choice Single Answer
Question: What is a data structure that controls the state of a collection of threads as a whole?
Correct Answer: Thread group
Your Answer: Thread group

Match The Following
Question Correct Answer Your Answer
currentThread member of thread member of thread
High priority thread preemptive multitasking thread's priority
getName thread's name thread's name
isAlive thread is still running thread is still running

Multiple Choice Single Answer
Question: How do you assign values to variables?
Correct Answer: By using the assignment operator =.
Your Answer: By using the assignment operator =.

Multiple Choice Single Answer
Question: Which of the following is used to get the value of the instance variables?
Correct Answer: Dot Notation
Your Answer: Semi colon

Multiple Choice Multiple Answer
Question: Which are the keywords use in switch statement?
Correct Answer: Case , Default
Your Answer: Case , Default

Multiple Choice Multiple Answer
Question: The source for the frist package defines three classes
Correct Answer: Protection , Derived , SamePackage
Your Answer: Method , Derived , SamePackage

Multiple Choice Multiple Answer
Question: The Stack performs which two function?
Correct Answer: pop( ) , push( )
Your Answer: pop( ) , push( )

Select The Blank
Question: ________ variables are declared by use of the Byte Keyword.
Correct Answer: Byte
Your Answer: Byte

Select The Blank
Question: The ________ repeats a set of code at least once before the condition is tested.
Correct Answer: Do-while loop
Your Answer: Do-while loop

Multiple Choice Single Answer
Question: What is a string?
Correct Answer: A combination of characters called as string
Your Answer: A combination of characters called as string

Multiple Choice Single Answer
Question: How multidimensional array is declared?
Correct Answer: int[4] [5];
Your Answer: int[4] [5];

Multiple Choice Single Answer
Question: A thread name can be obtained by caling which method?
Correct Answer: getName( )
Your Answer: getName( )

True/False
Question: A thread can voluntarily relinquish control.
Correct Answer: False
Your Answer: False

Multiple Choice Single Answer
Question: Which cast must be used to convert a larger value into a smaller one?
Correct Answer: Explicit cast.
Your Answer: simplific cast

Multiple Choice Multiple Answer
Question: Modulus operator % can be applied to these data types :-
Correct Answer: floating Point , Integer , Character
Your Answer: floating Point , Integer , Character

True/False
Question: Suppose a given instance variable has been declared private, this instance variable is manipulated by methods outside its class.
Correct Answer: False
Your Answer: False

True/False
Question: Integer can Cast to byte value.
Correct Answer: False
Your Answer: True

Multiple Choice Single Answer
Question: How many concrete classes can you have inside an interface?
Correct Answer: none
Your Answer: three

Multiple Choice Single Answer
Question: When java program starts up, which thread begins running immediately?
Correct Answer: Main thread
Your Answer: Main thread

Multiple Choice Single Answer
Question: Which operator is used to create and concatenate string?
Correct Answer: Addition operator(+).
Your Answer: Addition operator(+).

Select The Blank
Question: After calling start( ) NewThread, constructor returns to ________.
Correct Answer: main( )
Your Answer: main( )

Multiple Choice Single Answer
Question: How to change the values of the elements of the array?
Correct Answer: By using array subscript expression
Your Answer: By specifying index number

Multiple Choice Single Answer
Question: How can class be imported from a package to a program?
Correct Answer: import java.packagename.classname
Your Answer: import java.packagename.classname

True/False
Question: Is it necessary to implement all the methods of an interface while implementing the interface
Correct Answer: False
Your Answer: False

Multiple Choice Single Answer
Question: A Java application can execute anywhere on the network, this implements that Java is :-
Correct Answer: Architecture neutral
Your Answer: Architecture neutral

True/False
Question: Interface can be extended.
Correct Answer: True
Your Answer: True

Select The Blank
Question: A class can only inherit a single ________.
Correct Answer: Superclass
Your Answer: Superclass

Multiple Choice Multiple Answer
Question: Exit statement is optional in which loops in java?
Correct Answer: While , Do-while , For
Your Answer: While , Do-while , For

True/False
Question: Java allows loops to be nested.
Correct Answer: True
Your Answer: True

Multiple Choice Single Answer
Question: What is an array?
Correct Answer: It is value collection of same type of data type
Your Answer: It is value collection of same type of data type

Select The Blank
Question: ________ loop repeats a statement or block while its controlling expressions is true.
Correct Answer: While
Your Answer: Do-while

True/False
Question: A thread can be blocked when waiting for a resource.
Correct Answer: True
Your Answer: True

Select The Blank
Question: A ________ is declared by use of the class keyword.
Correct Answer: class
Your Answer: class( )

Select The Blank
Question: Double data type uses ________ to store a value
Correct Answer: 64 bits
Your Answer: 64 bits

Multiple Choice Multiple Answer
Question: Packages act as containers for :-
Correct Answer: Classes , Subordinate packages
Your Answer: Classes , Subordinate packages , Subclasses

Select The Blank
Question: The mechanism by which java frees the memory occupied by unused objects is ________.
Correct Answer: Garbage Collection
Your Answer: Garbage Collection

Select The Blank
Question: The explicit drop of an object reference by setting the value of a variable, whose data type is a reference type of ________.
Correct Answer: Null
Your Answer: Instance

Multiple Choice Single Answer
Question: How many types of literals are there?
Correct Answer: Number literals, character literals, boolean literals, string literals, etc.
Your Answer: Number literals, character literals, boolean literals, string literals, etc.

Multiple Choice Single Answer
Question: How array is defined?
Correct Answer: int arr[];
Your Answer: int arr[];

Multiple Choice Single Answer
Question: What are primitive data types?
Correct Answer: byte, short, int, long
Your Answer: byte, short, int, long

Multiple Choice Multiple Answer
Question: Which of the following is the declaration of an array of string objects?
Correct Answer: String[ ] s; , String [ ]s: , String[ s]: Your Answer: String[ ] s; , String [ ]s: , String[ s]: