If you have been to couple of Java interviews then you know that there are some questions which keep repeating e.g. difference between == and equals() method and may of it's popular cousins like HashMap vs Hashtable, ArrayList vs LinkedList, difference between equals() and hashCode(), or difference between Comparator and Comparable in Java. I call them frequently asked Java interview questions, and I suggest every Java developer to make a list of them for their own reference and revision. I am sure many Java programmer already has such list of questions handy, if not this is a good time to find and make your own list. These are the questions which you simply can't afford to miss, especially at freshers level. They appear at various stage of Java interviews. Most likely you will see them on telephonic round, where Interviewer just want to filter candidates between who knows Java and who doesn't. Good thing about them is that they are so common that everyone knows about it. Though for freshers it could be little difficult. but as your experience grows these frequently asked questions become much easier to answer. Some programmers also prefer to collect frequently asked Java questions based upon topics e.g. common questions from threads, strings, collections and other popular Java interview topics, some of them are already shared by me. In this list, I am sharing some of the most frequently asked questions from Java interviews. By the way, when you look the list, you will see some of the classics are missing e.g. difference between String and StringBuffer, but there are many like that, and that is task for you to collect as many as possible and keep them handy to avoid searching from them just before interview. I will also add some more questions on this list but for now let's start with these 21 questions.