41. Explain the concept of ‘varargs’ in Java, and how are they used in method parameters?

  •  ‘varargs’ allow you to pass a variable number of arguments to a method. They are specified by using an ellipsis (…) after the argument type.

42. What is a ‘lambda expression’ in Java, and how is it used in functional programming?

  •  A lambda expression is a concise way to define anonymous functions. They are used with functional interfaces to enable functional programming in Java.

43. Explain the ‘Method Reference’ feature introduced in Java 8 and its usage.

  •  Method references allow you to reference methods using different types of expressions, simplifying code when working with functional interfaces.

44. What is the ‘Iterable’ and ‘Iterator’ interface in Java, and how are they related?

  •  ‘Iterable’ is an interface that represents a sequence of elements, and ‘Iterator’ is used to traverse the elements in an ‘Iterable’ collection.

45. What is ‘Java Naming and Directory Interface (JNDI)’ and its use in Java applications?

  •  JNDI is an API for accessing naming and directory services, allowing Java applications to look up and interact with objects in a directory.

46. What is the ‘ClassLoader’ hierarchy in Java, and how does class loading work in a multi-classloader environment?

  •  The ‘ClassLoader’ hierarchy in Java consists of Bootstrap, Extension, and System class loaders. Classes are loaded in a parent-child relationship, with delegation to parent class loaders.

47. Explain the ‘break’ and ‘continue’ statements in Java, and provide examples of their usage.

  •  ‘break’ is used to exit a loop or switch statement, and ‘continue’ is used to skip the current iteration of a loop. Examples are often used in loops for control flow.

48. What is the ‘try-with-resources’ statement in Java, and how does it help with resource management?

  •  ‘try-with-resources’ is used to manage resources like streams and connections. It automatically closes resources when the block is exited, improving resource management.

49. Explain the ‘StringTokenizer’ class in Java and its use for tokenizing strings.

  •  ‘StringTokenizer’ is a legacy class used to break a string into tokens or words based on delimiters. It’s often used for text processing.

50. What is the purpose of the ‘assert’ statement in Java, and how can it be enabled or disabled?

  •  The ‘assert’ statement is used for debugging and is enabled with the ‘-ea’ JVM option. It allows you to check assumptions and throw an AssertionError if they fail.