Tata Consultancy Services Senior Software Engineer - Java Developer interview questions

Here’s a categorized list of Java Developer interview questions, covering core concepts, OOP, collections, multithreading, and more—suitable for beginner to intermediate-level roles: --- Core Java 1. What are the main features of Java? 2. Explain the JVM, JRE, and JDK. 3. What is the difference between == and .equals() in Java? 4. What is autoboxing and unboxing? 5. What are wrapper classes? --- Object-Oriented Programming (OOP) 1. Explain the four pillars of OOP in Java. 2. What is method overloading and method overriding? 3. What is the difference between abstract class and interface? 4. Can we create an object of an abstract class? 5. What is the use of super and this keywords? --- Exception Handling 1. What is the difference between checked and unchecked exceptions? 2. What is the use of finally block? 3. Can we have multiple catch blocks for a single try? 4. What is the difference between throw and throws? --- Collections Framework 1. What is the difference between ArrayList and LinkedList? 2. How does HashMap work internally? 3. What is the difference between HashMap and Hashtable? 4. What are the differences between Set