S.No | Question |
---|---|
1. | What is Java? Explain its key features. |
2. | How is Java platform-independent? Explain the role of the Java Virtual Machine (JVM). |
3. | What is the JVM? Explain its role in executing Java programs. |
4. | What is the JDK? What components does it consist of? |
5. | What is the JRE? What is its purpose? |
6. | What are JavaDocs? How do you generate and use them? |
7. | Explain the structure of a Java program. What are the main components? |
8. | How do you compile and run a simple "HelloWorld" program in Java? |
9. | What are the different data types in Java? Explain their sizes and ranges. |
10. | How do you declare and use variables in Java? |
11. | What are constants in Java? How do you declare and use them? |
12. | Explain arithmetic operators in Java and provide examples. |
13. | What are relational operators in Java? How do you use them for comparison? |
14. | What are logical operators in Java? How do you use them for logical operations? |
15. | How do you use the increment and decrement operators in Java? |
16. | Explain the assignment operators in Java and provide examples. |
17. | What are bitwise operators in Java? How do you use them for bitwise operations? |
18. | Explain the operator precedence and evaluation order in Java. |
19. | Provide examples to illustrate the precedence and order of evaluation. |
20. | What is type conversion in Java? Explain implicit and explicit type conversions. |
21. | How do you perform type casting in Java? |
22. | Explain the boolean data type in Java. What are its possible values? |
23. | How do you declare and use variables of type char in Java? |
24. | How do you read user input in Java? Explain the usage of the Scanner class. |
25. | How do you use the if-else statement in Java? Provide examples. |
26. | What is the conditional operator in Java? How do you use it? |
27. | What is the switch statement in Java? How do you use it? Provide examples. |
28. | How do you use the for loop in Java? Explain its syntax and usage. |
29. | What are the while and do-while loops in Java? How do you use them? |
30. | Explain the usage of the break and continue statements in Java loops. |
31. | What is an array in Java? How do you declare and initialize arrays? |
32. | How do you find the length of an array in Java? |
33. | Explain one-dimensional arrays in Java. How do you access and modify array elements? |
34. | What are multi-dimensional arrays in Java? How do you declare and use them? |
35. | What is a jagged array in Java? Provide an example and explain its usage. |
36. | What are objects and classes in Java? Explain their relationship. |
37. | How do you create objects and define classes in Java? |
38. | What is encapsulation in Java? How does it achieve data hiding? |
39. | Explain the concept of inheritance in Java. How do you implement it? |
40. | What is polymorphism in Java? Explain static and dynamic polymorphism. |
41. | How do you declare a class in Java? Explain the steps involved in compilation, loading, and execution of a Java program. |
42. | How do object references work in Java? Explain object allocation and the role of the heap. |
43. | What are instance variables and class variables in Java? How are they different? |
44. | Explain instance methods and class methods in Java. How do you define and use them? |
45. | What is a constructor in Java? Explain default and parameterized constructors. |
46. | What is the "this" keyword in Java? How is it used? |
47. | What is a static block in Java? Explain the purpose of default initialization blocks. |
48. | How does polymorphism work in Java? Explain method overloading. |
49. | How do you define and use methods that take objects as arguments in Java? |
50. | What is the "has-a" relationship in Java? Explain its significance in object-oriented programming. |
51. | How do you create an array of objects in Java? How do you iterate over it using the for-each loop? |
52. | How do you define and use methods that take arrays as arguments in Java? |
53. | What are variable argument methods in Java? How do you declare and use them? |
54. | What are inner classes in Java? Explain static, member, and local inner classes. |
55. | Explain the concept of inheritance in Java. How do you declare and use inheritance using the "extends" keyword? |
56. | What is method overriding in Java? How do you use the "super" keyword in method overriding? |
57. | Can constructors be overridden in Java? Explain the role of the "super" keyword in constructor overriding. |
58. | How does multilevel inheritance work in Java? Explain constructor chaining in inheritance. |
59. | What are references of super types in Java? How does dynamic polymorphism work with these references? |
60. | What is the "instanceof" operator in Java? How is the "final" keyword used? |
61. | What are abstract classes in Java? How do you define and use them? |
62. | What is an interface in Java? How do you define and implement interfaces? |
63. | What are anonymous inner classes in Java? How do you use them? |
64. | How do you organize classes in packages in Java? Explain the purpose of packages. |
65. | What are the different access protection levels in Java? Explain private access and the use of getters and setters. |
66. | Explain protected and public access modifiers in Java. |
67. | How do you create subpackages in Java? Explain their purpose. |
68. | How do you compile Java packages? How do you create and run a .jar file? |
69. | Explain the java.lang package in Java. What are the methods available in the String class? |
70. | What is the Object class in Java? Explain the methods provided by the Object class, such as toString, equals, and hashCode. |
71. | What are wrapper classes in Java? Explain the purpose of Integer, Float, Boolean, and other wrapper classes. |
72. | How do you pass command-line arguments to a Java program? Explain their usage. |
73. | What is an exception in Java? Explain the role of the JVM in exception handling. What are the types of exceptions in Java? |
74. | How do you handle exceptions in Java using try, catch, and finally blocks? Explain common exceptions like NullPointerException, ArrayIndexOutOfBoundsException, and FileNotFoundException. |
75. | What is the difference between throw and throws in Java exception handling? |
76. | How do you create custom exceptions in Java? Explain checked and unchecked exceptions. |
77. | How do you handle multiple exceptions in Java? Explain the usage of multiple catch blocks. |
78. | What is multithreading in Java? Explain the concepts of the operating system, process, application, and thread. |
79. | How do you create and execute threads using the Thread class in Java? |
80. | How do you create and execute threads using the Runnable interface in Java? |
81. | Explain the methods sleep, join, and interrupt in Java thread handling. |
82. | What is thread synchronization in Java? How do you achieve thread synchronization? |
83. | How do you set thread names and priorities in Java? Explain the different thread states. |
84. | What is the concept of streams in Java IO? Explain the types of streams. |
85. | How do you read text and binary input streams in Java? Explain the usage of standard input. |
86. | How do you write text and binary output streams in Java? Explain the usage of standard output. |
87. | How do you read and write text files in Java? |
88. | How do you read and write binary files in Java? |
89. | What are DataInputStream and DataOutputStream in Java IO? How do you use them? |
90. | How do you read and write objects using ObjectInputStream and ObjectOutputStream in Java? |
91. | Explain serialization in Java. How do you serialize and deserialize objects? Discuss other streams in Java IO. |
92. | What are generics in Java? Explain their purpose in type safety and code reusability. |
93. | How do you define and use generic types in Java? |
94. | How do you define and use generic methods in Java? |
95. | What are bounded type parameters in Java generics? Explain their usage. |
96. | How does inheritance work with generic types in Java? Explain subtyping. |
97. | What are wildcards in Java generics? How do you use them? |
98. | What is the concept of collections in Java? Explain the class hierarchy of collections. |
99. | Explain the List interface and its subclasses in Java collections. |
100. | How do you iterate over collections in Java? Explain the usage of the for-each loop and Iterator. |
101. | What is the Queue interface in Java collections? Explain its subclasses and their usage. |
102. | Explain the Set interface and its subclasses in Java collections. |
103. | What is the Map interface in Java collections? Explain its subclasses and their usage. |
104. | What are Comparator and Comparable in Java collections? How do you use them for sorting? |
105. | Explain the collection algorithms available in Java. How do you use them for searching, sorting, and manipulating collections? |
Office no.- 401,Shekhar Central Building ,Palasiya, Pin-code:452001, Indore
contact@codebetter.in
+91 88230 75444, +91 99939 28766