"Core Java Essentials" are something you must know, and know it well to succeed as a Java professional. Even 40% to 60% of the so called experienced professionals fail to make an impression due to their lack of understanding in one or more of the areas covered in this book. Lack of good understanding in the core essentials can be a speed breaker to your career advancement. If you have a java interview coming up in a few days or you want to impress your peers and superiors with your technical strengths during code review sessions, team meetings, and stand-ups, and concerned about how to make a good impression? You don't need to worry if you are familiar with the fundamentals. This is a Questions & Answers book with 250+ questions and answers relating to core Java with lots of code snippets (100+), examples, and diagrams. Most Java interviews and technical challenges you face at work are structured around the fundamentals and how well you communicate those fundamentals. So regularly brushing up on these fundamentals really pays off. Your analytical, problem solving, and coding skills will also be under scrutiny along with your ability to get the job done with the right tools. If your fundamentals are clear and know what tools to use, you can tackle any questions, and find solutions to any problems and challenges you face. Even if you don't have the exact answer for a problem, you will know how to go about solving them with a little research if you have a solid grounding in the fundamentals covered in this book. A little preparation can make a huge difference to your career success. Preparation can help you communicate your thoughts more clearly with examples and illustrations. Preparation can make a good and lasting impression on those who talk with you during your interviews and team meetings. This impression will be partly influenced by how prepared you are and how knowledgeable you are about your industry and the challenges it faces. It will also be influenced by your appearance, attitude, enthusiasm, and confidence. Good preparation breeds confidence and it shows in the interviews and team meetings. So prepare well in advance if you just begun to see yourself in your dream company or would like to go places in your chosen field.