After Completion This Course You Can Answer All The Below Questions:
1. What is Data hiding?
2. What is Abstraction?
3. What is Encapsulation?
4. Explain the advantages and disadvantages of Encapsulation?
5. What is tightly encapsulated class?
6. What is IS-A relationship?
7. Which keyword is used for IS-A relationship?
8. What are various advantages of IS-A relationship?
9. Explain about HAS-A relationship?
10. What is composition?
11. What is aggregation?
12. What is method signature?
13. What is overloading?
14. What are various rules satisfied by overloaded methods?
15. What is static polymorphism (or) compile-time polymorphism (or) early binding?
16. Differentiate IS-A and HAS-A relationships?
17. Is it possible to overload main() method?
18. In overloading whether jvm or compiler is responsible for method resolution?
19. What is overriding?
20. What is runtime polymorphism or dynamic polymorphism or late binding?
21. What are various rules satisfied by overriding methods?
22. Is it possible to override the following methods ? final methods , abstract methods synchronized methods ,native methods ,strictfp methods , private methods .
23. What are co-variant return types?
24. While overriding is it compulsory to maintain same return type?
25. In overriding who is responsible for method resolution?
26. What is dynamic method dispatch?
27. If parent class method throws some checked exception while overriding is it
compulsory should throw child class method the same checked exception?
28. Is it possible to overriding constructor?
29. Is it possible to overriding non-abstract method as abstract ?
30. Is it possible to override a var-arg method with a general method?
31. Is it possible to override static method?
32. What is method hiding?
33. Explain differences b/w overriding and method hiding?
34. Is it possible to override main() method?
35. Is it possible to override a variable?
36. Who is responsible for variable resolution?
37. What are key differences b/w overriding and overloading?
38. Explain various activities which are executed while loading the class?
39. When ever we are loading child class is it required to load parent class?
40. When ever we are loading parent class is it required to load child class?
41. What is purpose of static block and explain its requirement with examples?
42. Is it possible to take multiple static blocks in the same java class?
43. When the static blocks will be executed?
44. Whit out using main() method is it possible to print some statements to console?
45. Whit out using main() and static blocks is it possible to print some statements?
46. What is instance block when it will be executed?
47. Difference b/w instance block and static block?
48. When ever we are creating an object what are various steps will be executed
internally?
49. Difference b/w constructor and instance block?
50. What is coupling?
51. Is it recommended tight coupling or loose coupling?
52. What is cohesion?
53. Is it recommended high cohesion or low cohesion?
54. Explain about object type casting and what are various rules we have to follow while performing type casting?
55. Is it possible to type cast parent object to the child type?
56. Is it possible to type cast child object to the parent type?
57. Explain the main important oops concepts?
58. What is the purpose of constructor?
59. Explain about default constructor and its prototype?
60. Is compiler generates default constructor always?
61. Is it possible to take return type for the constructor?
62. If we are taking return type to the constructor what will happen?
63. Explain about super() and this() ?
64. Is it possible to overload constructors?
65. Is inheritance concept applicable for constructor?
66. What are various modifiers applicable for constructors?
67. Where we can use private constructors?
68. What is singleton class and give an example?
69. Is it possible to create our own singleton class and explain the process?
70. What is factory method?
71. Explain about recursive constructor invocation?
72. If parent class constructor throws some checked exception is it compulsory to require
to throw that exception by child class constructor?
73. Is the first line in constructor is always super?
74. Is it possible to write a constructor in abstract class?
75. We can’t create an object of abstract class what is the need of constructor in abstract
class?
76. Is it possible to place constructor in an interface?
77. What is an Exception?
78. What is the purpose of Exception Handling?
79. What is the meaning of Exception Handling?
80. Explain Default Exception Handling Mechanism in java?
81. What is the purpose of try?
82. What is the purpose of catch block?
83. Is try with multiple catch block is possible?
84. If try with multiple catch block present is order of catch blocks important in which order we have to take?
85. What are various methods to print Exception information? And differentiate them.
86. If an exception raised inside catch block then what will happen?
87. Is it possible to take try, catch inside try block?
88. Is it possible to take try, catch inside catch block?
89. Is it possible to take try without catch?
90. What is the purpose of finally block?
91. Is finally block will be execute always?
92. In which situation finally block will not executed?
93. If return statement present inside try is finally block will be executed?
94. What is the difference between final, finally and finalize ()?
95. Is it possible to write any statement between try-catch and finally?
96. Is it possible to take two finally blocks for the same try?
97. Is syntax try-finally-catch is valid?
98. What is the purpose of throw?
99. Is it possible to throw an Error?
100. Is it possible to throw any java object?
101. After throw is it allow to take any statement directly?
102. What is the purpose of throws?
103. What is the difference between throw and throws?
104. What is the difference between throw and thrown?
105. Is it possible to use throws keyword for any java class?
106. If we are taking catch block for an exception but there is no chance of rising that exception in try then what will happen?
107. Explain Exception handling keywords?
108. Which class act as root for entire java Exception hierarchy?
109. What is the difference between Error and Exception?
110. What is difference between checked exception and unchecked exception?
111. What is difference between partially checked and fully checked Exception?
112. What is a customized Exception?
113. Explain the process of creating the customized Exception.
114. Explain control flow in try, catch, finally.
115. Can you give the most common occurred exception in your previous project?
116. Explain the cases where you used Exception handling in your previous project?
117. What is multitasking?
118 What is multithreading and explain its application areas?
119. What is advantage of multithreading?
120. When compared with c++ what is the advantage in java with respect to multithreading?
121. In how many ways we can define a thread?
122. Among extending Thread and implementing Runnable which approach is recommended?
123. Difference b/w t.start () and t.run ()?
124. Explain about thread Scheduler?
125. If we are not overriding run () what will happen?
126. Is it possible overloading of run ()?
127. Is it possible to override a start () method and what will happen?
128. Explain life cycle of a thread?
129. What is the importance of Thread class start () method?
130. After starting a thread if we try to restart the same Thread once again what will happen?
131. Explain Thread class constructors?
132. How to get and set name of a thread?
133. Who uses thread priorities?
134. Default priority for main thread?
135. Once we create a new thread what is its priority?
136. How to get priority from thread and set priority to a thread?
137. If we are trying to set priority of thread as 100, what will happen?
138. If two threads having different priority then which thread will get chance first for execution?
139. If two threads having same priority then which thread will get chance first for execution?
140. How we can prevent thread from execution?
141. What is yield () and Explain its purpose?
142. Is join is overloaded?
143. Purpose of sleep () method?
144. What is synchronized keyword? Explain its advantages and disadvantages?
145. What is object lock and when it is required?
146. What is a class level lock when it is required?
147. While a thread executing any synchronized method on the given object is it possible to execute remaining synchronized methods on the same object simultaneously by other thread?
148. Difference b/w synchronized method and static synchronized method?
149. Advantages of synchronized block over synchronized method?
150. What is synchronized statement?
151. How two threads will communicate with each other?
152. wait (), notify (), notifyAll () are available in which class?
153. Why wait (), notify (), notifyAll () methods are defined in Object instead of thread class?
154. Without having the lock is it possible to call wait ()?
155. If a waiting thread gets notification then it will enter into which state?
156. In which methods thread can release lock?
157. Explain wait (), notify () & notifyAll ()?
158. Difference between notify () & notifyAll ()?
159. Once a thread gives notification then which waiting thread will get a chance?
160. How a thread can interrupt another thread?
161. What is deadlock? Is it possible to resolve deadlock situation?
162. Which keyword causes deadlock situation?
163. How we can stop a thread explicitly?
164. Explain about suspend () and resume ()?
165. What is starvation and explain difference between deadlock & starvation?
166. What is race condition?
167. What is daemon thread? Give an example purpose of Daemon Thread?
168. How we can check daemon nature of a Thread? Is it possible to change Daemon nature of a Thread? Is main thread daemon (or) non-daemon?
169. Explain about ThreadGroup?
170. What is ThreadLocal?
171. What is your favorite package?
172. What is your favorite class?
173. When ever we are printing object reference which method will be execute?
174. In Object class how the toString () method is implemented?
175. Purpose of toString () method?
176. What is hashCode of an object? Where it will be useful?
177. Is it possible to override hashCode () method in our class?
178. Relation b/w toString () and hashCode ()?
179. Does hashCode represent address of an object?
180. What is the purpose of equals () method?
181. In object class how equals () is implemented?
182. Is it possible to override equals ()?
183. Relations b/w == operator and equals ()?
184. Difference b/w == and equals ()?
185. What is contract b/w equals () and hashCode ()?
186. In which case we can override equals ()?
187. When ever we are overriding equals () which method we have to override?
188. What is cloning? How we can perform cloning?
189. What is cloneable interface?
190. Proper way of overriding hashCode ()?
191. In which case we can override equals ()?
192. Difference b/w deepcloning and shallowcloning?
193. In your previous project where you used the following method toString (), hashCode (), equals (), clone ()?
194. What are various methods present in java.lang.Object ?
195. What are limitation of object Arrays?
196. What are differences between arrays and collections?
197. What are differences between arrays and ArrayList?
198. What are differences between arrays and Vector?
199. What is Collection API?
200. What is Collection framework?
201. What is difference between Collections and Collection?
202. Explain about Collection interface?
203. Explain about List interface?
204. Explain about Set interface?
205. Explain about SortedSet interface?
206. Explain about NavigableSet?
207. Explain about Queue interface?
208. Explain about Map interface?
209. Explain about SortedMap?
230. Explain about NavigableMap?
231. Explain about ArrayList class?
232. What is RandomAccess Interface?
233. Explain about LinkedList class?
234. Explain about Vector class?
235. What is difference between ArrayList and Vector?
236. How we can get synchronized version of ArrayList?
237. What is difference between size and capacity of a Collection Object?
238. What is difference between ArrayList and Linked List?
239. What are legacy classes and interfaces present in Collections framework?
240. What is difference Enumeration and Iterator?
241. What are limitations of Enumeration?
242. What is difference between enum and Enumeration?
243. What is difference between Iterator and ListIterator?
244. What is relation between ListIterator and Iterator?
245. Explain about HashSet class?
246. If we are trying to insert duplicate values in Set what will happen?
247. What is LinkedHashSet?
248. What is difference between HashSet and LinkedHashSet?
249. What are major enhancements in 1.4 version of collection frame work?
250. Explain about TreeSet?
251. What are differences between List and Set interfaces?
252. What is Comparable interface?
253. What is Comparator interface?
254. What are differences between Comparable and Comparator?
255. What is difference between HashSet and TreeSet?
256. What is Entry interface?
257. Explain about HashMap?
258. Explain about LinkedHashMap?
259. What are the differences between HashMap and LinkedHashMap?
260. What are the differences between HashMap and Hashtable?
261. What is IdentityHashMap?
261. What is difference between HashMap and IdentityHashMap?
262. What is WeakHashMap?
263. What is difference between HashMap and WeakHashMap?
264. What is TreeMap?
265. What is Hashtable?
266. What is PriorityQueue?
267. What is Arrays class?
268. We are planning to do an indexed search in a list of objects. Which of the two Java collections should you use: ArrayList or LinkedList?
269. Why ArrayList is faster than Vector?
270. How we can sort the elements of list?
271. How we can reverse the order of elements of a list?
272. Explain about Collections class?
273. What is the b/w reverse () and reverseOrder () present in Collections class?
274. xplain about Arrays class?
275. How we can implement sorting for arrays?
276. Is it possible to convert collection object to Array?
277. Is it possible to convert array into ArrayList form?
278. Explain about binarySearch() method available in Collections and Arrays classes?
279. What is the difference b/w index and insertion point?
280. What is load-factor?
281. For the top level classes which modifiers are allowed?
282. Is it possible to declare a class as static, private, protected?
283. What are extra modifiers applicable inner classes when compared with outer classes?
284. What is a final class?
285. Explain the differences between final, finally& finalize?
286. Is every method present in final class is final?
287. Is every variable present inside a final class is final?
288. What is abstract class?
289. What is abstract method?
290. If a class contain at least one abstract method is it required to declared that class compulsory abstract?
291. If a class doesn’t contain any abstract method is it possible to declare that class as abstract?
292. Whenever we are extending abstract class is it compulsory required to provide implementation for every abstract method of that class?
293. Is final class can contain abstract method?
294. Is abstract class can contain final methods?
295. Can u give example for abstract class which doesn’t contain any abstract method?
296. Which of the following modifiers combinations are legal for methods?
