Which Set class should be most popular in a multi-threading environment, considering performance constraint?
a.)HashSet  b.)ConcurrentSkipListSet  c.)LinkedHashSet  d.)CopyOnWriteArraySet
Which Map class should be most popular in a multi-threading environment, considering performance constraint?
a.)Hashtable  b.)CopyOnWriteMap  c.)ConcurrentHashMap  d.)ConcurrentMap
Which allows the removal of elements from a collection?
a.)Enumeration  b.)Iterator  c.)Both  d.)None of the above
In a stack, if a user tries to remove an element from an empty stack it is called _________
a) Underflow  b) Empty collection  c) Overflow  d) Garbage Collection
The self organizing list improves the efficiency of _______
a) binary search  b) jump search  c) sublist search  d) linear search
Symbol tables during compilation of program is efficiently implemented using __________
a) a singly linked list  b) a doubly linked list  c) a self organizing list  d) an array
The self organizing list improves _____
a) average access time  b) insertion  c) deletion  d) binary search
Which of these cannot be used for a variable name in Java?
a) identifier & keyword  b) identifier  c) keyword d) none of the mentioned
Which of the following is not a segment of memory in java?
a) Code Segment  b) Register Segment  c) Stack Segment  d) Heap Segment
Which exception is thrown when java is out of memory?
a) MemoryError  b) OutOfMemoryError  c) MemoryOutOfBoundsException  d) MemoryFullException
Which of these class is a superclass of every class in Java?
a) ArrayList class  b) Abstract class  c) Object class  d) String class
Which of these keywords can be used to prevent Method overriding in Java?
a) final  b) protected  c) static  d) constant
Which of these packages contains the exception Stack Overflow in Java?
a) java.io  b) java.system  c) java.lang   d) java.util
Which one of the following is not an access modifier?
a) Protected  b) Void  c) Public  d) Private
Which of this method of class String is used to obtain a length of String object?
a) get()  b) Sizeof()  c) lengthof()  d) length()
Which of these constructors is used to create an empty String object?
a) String()  b) String(void)  c) String(0)  d) None of the mentioned
Which of these is a method to clear all the data present in output buffers?
a) clear()  b) flush()  c) fflush()  d) close()
Which of these is a super class of Character wrapper?
a) Long  b) Digits  c) Float  d) Number
Which concept of Java is a way of converting real world objects in terms of class?
a) Polymorphism  b) Encapsulation  c) Abstraction  d) Inheritance
Which of this method is used to find out that a thread is still running or not?
a) run()  b) Alive()  c) isAlive()  d) checkRun()
Which of these method is used to implement Runnable interface?
a) stop()  b) run()  c) runThread()  d) stopThread()
Which of the following allows us to call generic methods as a normal method?
a) Type Interface  b) Interface  c) Inner class  d) All of the mentioned
Which of these is not a bitwise operator?
a) &  b) &=  c) |=  d) <=
Which of these keywords is used to define interfaces in Java?
a) intf  b) Intf  c) interface  d) Interface
Which of these access specifiers must be used for main() method?
a) private  b) public  c) protected  d) none of the mentioned
What is the process by which we can control what parts of a program can access the members of a class?
a) Polymorphism  b) Abstraction  c) Encapsulation  d) Recursion
Which of these access specifier must be used for class so that it can be inherited by another subclass?
a) public  b) private  c) protected  d) none of the mentioned
Which of this keyword must be used to inherit a class?
a) super  b) this  c) extent  d) extends
What is not type of inheritance?
a) Single inheritance  b) Double inheritance  c) Hierarchical inheritance  d) Multiple inheritance
If super class and subclass have same variable name, which keyword should be used to use super class?
a) super  b) this  c) upper  d) classname