? The "throw" keyword in Java is used to manually throw an exception, while the "throws" keyword is used in method declarations to specify that the method may throw certain types of exceptions. 42. What is the difference between checked exceptions and runtime exceptions? Checked exceptions are checked at compile-time and must be handled or declared, while runtime exceptions (unchecked exceptions) are not required to be handled or declared. 43. What is the Java API? The Java API (Application Programming Interface) is a collection of classes, interfaces, and other resources provided by the Java Development Kit (JDK). It provides a set of
predefined classes and methods for building Java applications. 44. What is the difference between an ArrayList and a LinkedList? An ArrayList is implemented as a resizable array, allowing fast random access but slower insertion and removal of elements. A LinkedList is implemented as a doubly- linked list, allowing fast insertion and removal but slower random access. 45. What is the difference between a HashSet and a TreeSet? A HashSet in Java stores elements in no particular order, using a hash table for fast access but does not maintain any specific order. A TreeSet stores elements in sorted order and allows for efficient retrieval of elements based on their natural ordering or a custom comparator. 46. What is the difference between the "equals()" method and the "hashCode()" method? The "equals()" method is used to compare the equality of objects based on their values, while the "hashCode()" method is used to calculate a unique hash code value for an object, typically used for efficient retrieval in hash-based data structures like
