Pregunta de entrevista de CitiusTech

1.Comparable vs Comparator 2.Questions of ConcurrentHashMap 3.Difference between Iterator and ListIterator 4.Immutability in Java 5.Java8 features 6.what is optional class 7.Transient,volatile Keyword use 8.What is functional Interface and why do we need it 9.Multithreading questions