Interview Questions.

Q1. What's New With The Stop(), Suspend() And Resume() Methods In Jdk 1.2?

The prevent(), suspend() and resume() techniques have been deprecated in JDK 1.2.

Q2. What Is The Range Of The Char Type?

The variety of the char kind is zero to two^sixteen - 1.

Q3. What Method Is Used To Specify A Container's Layout?

The setLayout() method is used to specify a box's layout.

Q4. What Is A Task's Priority And How Is It Used In Scheduling?

A project's priority is an integer price that identifies the relative order in which it ought to be completed with respect to other responsibilities. The scheduler tries to time table better precedence obligations before decrease priority duties.

Q5. What Is The Immediate Superclass Of The Applet Class?

Panel

Q6. When A Thread Blocks On I/o, What State Does It Enter?

A thread enters the waiting nation whilst it blocks on I/O.

Q7. How Many Bits Are Used To Represent Unicode, Ascii, Utf-16, And Utf-eight Characters?

Unicode requires sixteen bits and ASCII require 7 bits. Although the ASCII person set uses most effective 7 bits, it is also represented as eight bits. UTF-8 represents characters the usage of 8, sixteen, and 18 bit patterns. UTF-sixteen uses sixteen-bit and larger bit styles.

Q8. Can A Lock Be Acquired On A Class?

Yes, a lock may be received on a category. This lock is obtained at the magnificence's Class item.

Q9. What Is The Immediate Superclass Of The Dialog Class?

Window

Q10. What Is The Catch Or Declare Rule For Method Declarations?

If a checked exception may be thrown in the body of a technique, the approach ought to either trap the exception or claim it in its throws clause.

Q11. What Are Order Of Precedence And Associativity, And How Are They Used?

Order of priority determines the order wherein operators are evaluated in expressions. Associatity determines whether an expression is evaluated left-to-right or proper-to-left.

Q12. Which Java.Util Classes And Interfaces Support Event Handling?

The EventObject class and the EventListener interface help occasion processing.

Q13. Name Three Component Subclasses That Support Painting.

The Canvas, Frame, Panel, and Applet training aid painting.

Q14. What Is The Range Of The Short Type?

The variety of the short kind is -(2^15) to 2^15 - 1.

Q15. Which Method Of The Component Class Is Used To Set The Position And Size Of A Component?

SetBounds()

Q16. Can An Anonymous Class Be Declared As Implementing An Interface And Extending A Class?

An nameless magnificence may also enforce an interface or enlarge a superclass, however may not be declared to do each.

Q17. When A Thread Is Created And Started, What Is Its Initial State?

A thread is inside the prepared state after it has been created and commenced.

Q18. How Are Observer And Observable Used?

Objects that subclass the Observable class hold a list of observers. When an Observable object is up to date it invokes the update() technique of every of its observers to notify the observers that it has changed state. The Observer interface is applied by way of gadgets that observe Observable gadgets.

Q19. Is Null A Keyword?

The null fee isn't always a keyword.

Q20. What Class Is The Top Of The Awt Event Hierarchy?

The java.Awt.AWTEvent magnificence is the best-level elegance within the AWT occasion-magnificence hierarchy.

Q21. What Is The Immediate Superclass Of Menu?

MenuItem

Q22. In Which Package Are Most Of The Awt Events That Support The Event-delegation Model Defined?

Most of the AWT-related activities of the event-delegation model are described in the java.Awt.Occasion bundle. The AWTEvent magnificence is defined within the java.Awt package deal.

Q23. Why Do Threads Block On I/o?

Threads block on i/o (this is enters the waiting state) in order that other threads may additionally execute at the same time as the i/o Operation is completed.

Q24. Which Containers Use A Border Layout As Their Default Layout?

The window, Frame and Dialog lessons use a border layout as their default layout.

Q25. Which Characters May Be Used As The Second Character Of An Identifier, But Not As The First Character Of An Identifier?

The digits zero through nine won't be used as the first person of an identifier however they'll be used after the first character of an identifier.

Q26. How Does Java Handle Integer Overflows And Underflows?

It makes use of the ones low order bytes of the end result which could suit into the size of the type allowed by way of the operation.

Q27. Is Sizeof A Keyword?

The sizeof operator isn't a key-word.

Q28. What Is The Collections Api?

The Collections API is a fixed of lessons and interfaces that help operations on collections of items.

Q29. Does Garbage Collection Guarantee That A Program Will Not Run Out Of Memory?

Garbage collection does no longer guarantee that a software will now not run out of memory. It is feasible for packages to expend reminiscence sources faster than they're garbage collected. It is also viable for programs to create items that are not situation to rubbish series.

Q30. What Is The Difference Between The >> And >>> Operators?

The >> operator contains the sign bit while moving right. The >>> 0-fills bits which have been shifted out.

Q31. What Is Synchronization And Why Is It Important?

With respect to multithreading, synchronization is the functionality to manipulate the get right of entry to of a couple of threads to shared resources. Without synchronization, it's miles possible for one thread to adjust a shared item whilst every other thread is within the manner of the use of or updating that object's value. This often leads to full-size mistakes.

Q32. What Are Wrapped Classes?

Wrapped instructions are lessons that permit primitive types to be accessed as objects.

Q33. What Is A Transient Variable?

A brief variable is a variable that might not be serialized.

Q34. Can A For Statement Loop Indefinitely?

Yes, a for assertion can loop indefinitely. For example, consider the following:

for(;Wink ;

Q35. What Modifiers May Be Used With An Inner Class That Is A Member Of An Outer Class?

A (non-local) internal magnificence may be declared as public, covered, personal, static, final, or abstract.

Q36. Can An Object's Finalize() Method Be Invoked While It Is Reachable?

An item's finalize() technique cannot be invoked by the rubbish collector even as the item remains available. However, an object's finalize() technique may be invoked with the aid of different gadgets.

Q37. What Is The Difference Between Preemptive Scheduling And Time Slicing?

Under preemptive scheduling, the highest priority venture executes till it enters the waiting or useless states or a better priority project comes into lifestyles. Under time reducing, a challenge executes for a predefined slice of time and then reenters the pool of ready responsibilities. The scheduler then determines which project ought to execute next, based totally on precedence and different factors.

Q38. What Is An Iterator Interface?

The Iterator interface is used to step via the elements of a Collection.

Q39. What Is Clipping?

Clipping is the method of confining paint operations to a limited location or form.

Q40. What Is A Native Method?

A native method is a method this is implemented in a language other than Java.

 

Q41. What Is The List Interface?

The List interface affords aid for ordered collections of gadgets.

Q42. Which Containers Use A Flowlayout As Their Default Layout?

The Panel and Applet classes use the FlowLayout as their default layout.

Q43. What Value Does Readline() Return When It Has Reached The End Of A File?

The readLine() method returns null while it has reached the end of a record.

Q44. What State Does A Thread Enter When It Terminates Its Processing?

When a thread terminates its processing, it enters the lifeless state.

Q45. To What Value Is A Variable Of The String Type Automatically Initialized?

The default cost of an String type is null.

Q46. What Is The Vector Class?

The Vector magnificence gives the functionality to put into effect a growable array of gadgets.

Q47. What Is The Preferred Size Of A Component?

The desired length of a thing is the minimum component length that will permit the issue to display usually.

Q48. What Restrictions Are Placed On The Location Of A Package Statement Within A Source Code File?

A bundle announcement need to seem because the first line in a source code file (with the exception of blank lines and remarks).

Q49. What Is The Difference Between A Menuitem And A Checkboxmenuitem?

The CheckboxMenuItem class extends the MenuItem class to assist a menu item that may be checked or unchecked.

Q50. What Is The Difference Between Yielding And Sleeping?

When a assignment invokes its yield() approach, it returns to the geared up country. When a project invokes its sleep() method, it returns to the waiting country.