What is the Java Virtual Machine (JVM)?

The JVM is a runtime environment that executes Java bytecode and provides platform independence, memory management, and garbage collection for Java applications.

What is the difference between JDK and JRE?

The JDK includes tools for developing Java applications, while the JRE provides the runtime environment required to execute Java programs.

What are Java collections?

Java collections are data structures from the java.util package, such as List, Set, and Map, that provide methods for storing, accessing, and manipulating groups of objects.

Java Interview Questions

61. What are collections in Java?

62. What is the difference between List, Set, and Map?

63. How does ArrayList work internally?

64. How does LinkedList work internally?

65. What are HashMap internals?

66. How does hashing work in HashMap?

67. What are hash collisions and how are they handled?

68. What is the difference between HashMap and ConcurrentHashMap?

69. What are TreeMap and TreeSet?

70. What are generics in Java?