Studying programming

HashMap HashMap is not thread-safe which allows you faster speed than HashTable. HashMap doesn't allow insertion order. *Use LinkedHashMap to preserve the fixed order. key doesn't allow duplicate key, but for value, duplication is allowed. put() - key, value map에 입력 get() - key를 전달해야 그 key의 value가 반환된다. remove() - 해당 key의 key와 value 삭제 Example Code import java.util.*; public class Main { public ..

Collection Framework collection framework is a collection providing an architecture to store the group of objects.Java primitive types are not considered objects. Since Java collections only store objects, primitive types are not allowed to store. Thus, we need wrapper class or autoboxing to store data. Interfaces - Set,List,Queue,DequeClasses - ArrayList, Vector, LinkedList,HashSet,LinkedHashSe..