🍵🔝 💯➕ Java Interview Questions For Automation Testing 2024 🚀
Below are Top Java Interview Questions for Automation Testing covering all important topics of Java Programming Language:
1. What is Java?
2. What are the main features of Java?
3. What is the difference between JDK, JRE, and JVM?
4. What are the four main principles of Object-Oriented Programming?
5. What is inheritance in Java and how is it implemented?
6. Explain the concept of polymorphism in Java with an example.
7. What is encapsulation and why is it important?
8. Explain the concept of encapsulation with a real-world example.
9. What is the difference between a class and an object in Java?
10. Differentiate between abstract classes and interfaces in Java.
11. What is the difference between composition and inheritance?
12. How does Java support multiple inheritance?
13. How does Java support method overriding and why is it important?
14. What is a constructor in Java and what is its role in object creation?
15. What is the difference between a constructor and a method in Java?
16. Explain the concept of method overloading versus method overriding.
17. What is method hiding in Java, and how does it differ from method overriding?
18. How does Java support encapsulation, and why is it important in object-oriented programming?
19. Explain the concept of interfaces in Java and their role in object-oriented programming.
20. What is the difference between composition and aggregation in Java?
21. What is the difference between == and .equals() method in Java?
22. What is the difference between ArrayList and LinkedList?
23. What is the difference between checked and unchecked exceptions in Java?
24. What is the use of the final keyword in Java?
25. What is the purpose of the finalize() method in Java?
26. What is the purpose of the static keyword in Java?
27. What is the this keyword in Java?
28. How does Java support runtime polymorphism?
29. What are the principles of SOLID design, and how do they relate to object-oriented programming?
30. What is the difference between super() and this() in Java constructors?
31. What is the difference between public, protected, private, and default access modifiers in Java?
32. What are nested classes in Java, and what are their advantages?
33. What is the toString() method in Java, and why is it useful?
34. Explain the concept of method reference in Java 8.
35. What is a static initializer block in Java?
36. What is the difference between StringBuilder and StringBuffer classes?
37. What is a Collection in Java?
38. What are the main interfaces of the Java Collection framework?
39. Explain the concept of method chaining in Java.
40. What is a lambda expression in Java?
41. What is the difference between HashSet and TreeSet?
42. What are the differences between HashMap and HashTable?
43. What is the difference between Iterator and ListIterator?
44. What is the difference between fail-fast and fail-safe iterators?
45. What is the difference between == and equals() when comparing objects?
46. What is a package in Java?
47. What is the difference between == and equals() for comparing strings in Java?
48. What is the significance of the super keyword in Java?
49. Explain method hiding in Java.
50. What is a Java annotation?
51. What is the transient keyword in Java?
52. What is the volatile keyword in Java?
53. What is the purpose of the finalize() method in Java?
54. What is the instanceof operator in Java used for?
55. Explain the difference between == and .compareTo() when comparing two objects in Java.
56. What are anonymous classes in Java?
57. What are the access modifiers for constructors in Java?
58. What is the purpose of the enum keyword in Java?
59. Explain the difference between throw and throws in Java.
60. What is the purpose of the strictfp keyword in Java?
61. What is the @Override annotation used for in Java?
62. Explain the try-with-resources statement in Java.
63. What is the difference between a deep copy and a shallow copy in Java?
64. What is the purpose of the assert keyword in Java?
65. What is the java.lang.Object class in Java?
66. What are generics in Java?
67. What is type erasure in Java generics?
68. What are wildcards in Java generics?
69. What is the ClassLoader in Java?
70. What is the difference between Array and ArrayList in Java?
71. What is the purpose of the java.util.Collections class in Java?
72. Explain the difference between HashSet and HashMap in Java.
73. What is the difference between Arrays.asList() and ArrayList?
74. What is the purpose of the Deque interface in Java?
75. What is the difference between poll(), peek(), and remove() methods in the Queue interface?
76. How does the HashMap class handle collisions?
77. Explain the purpose of the Iterator interface in Java collections.
78. Explain the difference between synchronized methods and synchronized blocks in Java.
79. What is the purpose of the java.lang.Runtime class in Java?
80. What is the purpose of the java.lang.Thread class in Java?
81. What is a daemon thread in Java?
82. Explain the difference between sleep(), yield(), and wait() methods in Java.
83. What is the purpose of the java.lang.Cloneable interface in Java?
84. Explain the concept of serialization and deserialization in Java.
85. What is the purpose of the java.nio package in Java?
86. Explain the concept of ByteBuffer in the context of java.nio package.
87. What are the advantages of using the java.util.concurrent package over traditional synchronization mechanisms?
88. What are the advantages of using the java.util.stream API introduced in Java 8?
89. Explain the concept of functional interfaces in Java.
90. What are lambda expressions and how are they used in Java?
91. Explain the concept of method references in Java.
92. Explain the concept of stream parallelism in Java.
93. Explain the concept of default methods in interfaces introduced in Java 8.
94. What is the purpose of static methods in interfaces introduced in Java 8?
95. What is the purpose of the java.util.concurrent.locks package in Java?
96. Explain the concept of thread confinement in Java concurrency.
97. What is the purpose of the java.time package in Java 8 and later versions?
98. What is the purpose of the java.util.function package in Java 8 and later versions?
99. What is the purpose of the java.util.regex package in Java?
100. What is the purpose of the java.util.Random class in Java?
✨You can read the answers to these questions in below link:👇
🌠Best Of Luck For Your Interview! 💼