best java interview questions in agn hub 100+

 

Core Java Concepts

1. What is the Java Virtual Machine (JVM)?
2. Explain the difference between JDK, JRE, and JVM.
3. What are the main features of Java?
4. What is a class in Java?
5. What is an object in Java?
6. Explain the concept of inheritance in Java.
7. What is polymorphism in Java?
8. What is encapsulation in Java?
9. What is abstraction in Java?
10. What are the different types of memory areas allocated by JVM?
11. What is the difference between heap memory and stack memory?
12. What is the significance of the main method in Java?
13. Explain the difference between a constructor and a method.
14. Can we overload the main method?
15. What is method overloading in Java?
16. What is method overriding in Java?
17. What is a static method?
18. Can we override static methods?
19. What is the difference between a static variable and an instance variable?
20. Explain the final keyword in Java.
21. What is the difference between == and equals() in Java?
22. What are the different access modifiers in Java?
23. What is the purpose of the this keyword?
24. What is the super keyword in Java?
25. What are wrapper classes in Java?
26. What is autoboxing and unboxing?
27. What is a package in Java?
28. What is the difference between import and static import?
29. What is an interface in Java?
30. Can we instantiate an interface?
31. What is the difference between an abstract class and an interface?
32. What is the purpose of the abstract keyword in Java?
33. What is the difference between ArrayList and Vector?
34. What is the difference between HashMap and Hashtable?
35. What is the purpose of the transient keyword?
36. What is the volatile keyword used for?
37. Explain the concept of serialization in Java.
38. What is a singleton class?
39. How can we create a singleton class in Java?
40. What is a Java Bean?
41. What is the difference between == and === in Java?
42. What are the types of constructors in Java?
43. What is the difference between throw and throws?
44. What is a marker interface?
45. What is the purpose of the default keyword in Java?

Exception Handling

46. What is an exception in Java?
47. Explain the difference between checked and unchecked exceptions.
48. What is the base class for all exceptions in Java?
49. What is the difference between throw and throws in Java?
50. Explain the concept of exception chaining.
51. What are the different ways to handle exceptions in Java?
52. What is the purpose of the finally block?
53. Can we have a try block without a catch block?
54. What is a custom exception in Java?
55. What is the use of try-with-resources in Java?

Multithreading

56. What is a thread in Java?
57. What is the difference between process and thread?
58. What is multithreading?
59. How can we create a thread in Java?
60. What is the difference between Runnable and Thread in Java?
61. What is the purpose of the synchronized keyword?
62. What is a thread pool?
63. What is the purpose of the wait(), notify(), and notifyAll() methods?
64. What is a daemon thread?
65. What is thread priority?
66. Explain the concept of thread synchronization.
67. What is a ReentrantLock in Java?
68. What is the Callable interface?
69. What is the Future interface in Java?
70. Explain the difference between sleep() and wait() methods in Java.

Collections Framework

71. What is the Collections Framework in Java?
72. What is the difference between ArrayList and LinkedList?
73. What is the difference between HashSet and TreeSet?
74. What is the difference between Queue and Deque?
75. What is the difference between Iterator and ListIterator?
76. What is a Comparator in Java?
77. What is a Comparable in Java?
78. What is the difference between HashMap and LinkedHashMap?
79. What is a TreeMap in Java?
80. What is the purpose of the Collections class?
81. What is the difference between fail-fast and fail-safe iterators?

Java 8 Features

82. What are the main features introduced in Java 8?
83. What is a lambda expression in Java?
84. What is a functional interface?
85. What is the Stream API?
86. Explain the concept of default methods in interfaces.
87. What are method references in Java?
88. What is the Optional class?
89. What is the java.time package?
90. Explain the concept of Collectors in Java.
91. What is the CompletableFuture class?

Advanced Topics

92. What is the Java Memory Model?
93. What is garbage collection in Java?
94. What are the types of garbage collectors in Java?
95. What is the difference between serial and parallel garbage collectors?
96. What is the G1 garbage collector?
97. Explain the concept of soft, weak, and phantom references.
98. What is the java.lang.ref package?
99. What is the JNI?
100. What is the JIT compiler?

Design Patterns

101. What is a design pattern in Java?
102. Explain the Singleton design pattern.
103. What is the Factory design pattern?
104. What is the Observer design pattern?
105. What is the Decorator design pattern?
106. Explain the Strategy design pattern.
107. What is the Prototype design pattern?
108. What is the Adapter design pattern?

Miscellaneous

109. What are enums in Java?
110. What is the Locale class?
111. What is the ResourceBundle class?
112. What is the Properties class?
113. What is reflection in Java?
114. What are annotations in Java?
115. What is the purpose of the volatile keyword?
116. What is the difference between System.out, System.err, and System.in?
117. Explain the concept of immutability.
118. What is a WeakHashMap?
119. What is the difference between String, StringBuilder, and StringBuffer?
120. What is the Path interface?
121. What is NIO in Java?
122. Explain the concept of memory leaks in Java.

best computer classes in near me

best computer center in jaipur 

best agn hub computer center 

best digital marketing in near me

computer traning center in jaipur 

best agn hub computer traning center in jaipur

Agn Hub Tech and IT Solutions

From Agn Hub Tech and IT Solutions

"AGN HUB The Best Computer Training Institute in Jaipur provides easiest way of Computer training that is why students can get computer language and other course knowledge easily. It is a project based training institute where students can learn programming and other courses with there school academics and enhance there knowledge with experience faculties and professional trainers. Services we offer are. Computer programming languages (72+) courses 1. Web Designing 2. Web Development 3. App Development 4. Python 5. C and C++ 6. PHP 7. React , Node JS, React Native 8. Digital Marketing(SEO,SMO,SMM,SEM,PPC) 9. Programming Language(R, Angular, Laravel) 10. Tuitions and coding for kids and many more... Get The Best Coding language Training"