This repository contains list of interview questions answered in my YouTube and Instagram videos.
- What is Functional Interface?
- Whether Java is Interpreted or Compiled language?
- What is Singleton class?
- What is the difference between throw vs throws?
- What is Object class?
- What is the difference between Mutable vs Immutable?
- What is HQL?
- How to create Immutable class in Java?
- What is final keyword?
- What is static keyword?
- What is the difference between method Overloading and Overriding?
- What is @SpringBootApplication annotation?
- What is the difference between Checked and Unchecked exception?
- What is N+1 problem?
- What is Serialization?
- What is Marker interface?
- Why do we need Interface and Abstract Class in Java?
- Can we have concrete methods in Java interface?
- What is Encapsulation?
- What is Abstraction?
- What is Inheritance?
- Can static methods be abstract in Java?
- What is @Override annotation in Java?
- What are the new features of Java 8?
- What is Streams API?
- What is Optional class?
- What is the difference between Comparable and Comparator?
- What is the difference between Eager Loading and Lazy Loading?
- Explain final, finally {} and finalize()?
- What are the new Java 9 features?
- What are the new Java 10 features?
- Why multiple inheritance is not allowed in Java?
- What is Hibernate Criteria API?
- What is volatile keyword?
- What is the difference between ArrayList and LinkedList?
- Can Java code be executed without generating .class file?
- What is the difference between HashSet, LinkedHashSet and TreeSet?
- What is the difference between JDK, JRE and JVM?
- Can we have default arguments in Java?
- Can a constructor be final in Java?
- What are the new Java 11 features?
- What is Classloader in Java?
- What is Primary Cache in Hibernate?
- Why String is immutable in Java?
- What is an Enum in Java?
- What is the difference between synchronized, volatile and atomic in Java?
- What is the difference between TDD and BDD?
- What is the difference between isEmpty() and isBlank()?
- Why StringBuffer is obsolete?
- What is Nested class in Java?
- What is Secondary Cache in Hibernate?
- How to prevent Singleton Pattern from Serialization?
- Explain try, catch and finally in Java?
- How to prevent Singleton Pattern from Cloning?
- What is a Constructor in Java?
- Can Constructors be overloaded?
- What is atomic variable in Java?
- How to prevent Singleton Pattern from Reflection?
- What is super keyword in Java?
- What is this keyword in Java?
- Can constructors have a return type?
- What is differnce between Stack memory and Heap memory?
- What is the difference between Hibernate and JPA?
- What is an Association in Java?
- What is an Aggregation in Java?
- What is Composition in Java?
- What is the difference between JDBC and Hibernate?
- What are Annotations in Java?
- What is DateTime API in Java?
- What are 4 main default Functional Interfaces in Java?
- What are stereotype annotations in Spring?
- What are Design Patterns in Java?
- What is Cloning in Java?
- What are Wrapper classes in Java?
- Does Java has Copy Constructor?
- What is Package in Java?
- What happens when the main() isn't declared as static?
- Difference between instance and local variables?
- What is Record in Java?
- What is Multithreading in Java?
- Explain Thread life cycle?
- What are Daemon Threads in Java?
- What is Garbage collection in Java?
- What is the difference between HashMap and Hashtable?
- What is the difference between Call By Value and Call By Reference?
- What is executor framework in Java?
- Why Java is Call by Value?
- How does Thread Pool reuse a thread?
- What is the difference between Runnable and Callable?
- Is Java still relevant in 2024?
- What is Race condition in Multithreading?
- What is Deadlock in Multithreading?
- What is Livelock in Multithreading?
- Can we create infinite threads in Java?
- What is Sealed class?
- What is typecasting in Java?
- What is hashcode() and equals() contract?
- What is Hashing?
- Explain internal working of HashSet?
- Explain internal working of HashMap?
- Why Java is not pure object oriented language?
- Why to use Getter and Setter methods?
- What are Parallel Streams in Java?
- What is a ForkJoinPool in Java?
- What is a ReentrantLock?
- What is the difference between PermGen and Metaspace in Java?
- What are Covariant return types?
- What is the difference between == and equals() in Java?
- What is Cyclic Dependency?
- What is Memory Leak in Java?
- What is Thread Safe code?
- What is ThreadLocal?
- What is Method Reference?
- What is Tight Coupling and Loose Coupling?
- What is Inversion of Control?
- What is Dependency Injection?
- What is a Bean in Spring Framework?
- What is Autowiring in Spring?
- What is @Qualifier?
- What if the bean mentioned in @Qualifier is not available?
- What is @Primary?
- What if the bean annotated with @Primary is not available?
- What is the difference between @Qualifier and @Primary?
- What are SOLID Principles?
- What is S in SOLID Principles?
- What is O in SOLID Principles?
- What is L in SOLID Principles?
- What is I in SOLID Principles?
- What is D in SOLID Principles?
- Is public static void main insignificant in Java now?
- What are ACID Properties?
- What is a String Pool?
- What is an Integer Pool?
- How does intern() method works?
- What is A in ACID Properties?
- What is C in ACID Properties?
- What is I in ACID Properties?
- What is D in ACID Properties?
- Can static variables be autowired in Spring?
- What is spring-boot-starter-parent?
- What is spring-boot-starter dependency?
- What is the difference between Spring and Spring Boot?
- What should we use in finance related logic - Double or BigDecimal?
- Why is it called classpath?
- Can we delete the application.properties file in Spring Boot?
- What is Scope in Spring Boot?
- What is Spring Initializr?
- What is CommandLineRunner?
- How to implement Logging in Spring Boot?
- What is ConcurrentHashMap?
- What is better: application.properties or application.yml?
- What is Aspect Oriented Programming?
- What is the difference between @Component and @Bean?
- How to sort 10GB of data with 1GB of RAM?
- Explain the working of MVC?
- What is the difference between @Controller and @RestController?
- What are Virtual Threads?
- What is @SpringBootTest?
- What is Spring Boot DevTools?
- What is Spring Data JPA?
- SQL to find employee with Nth highest salary?
- What is CompletableFuture?
- What is the difference between Future and CompletableFuture?
- What is Object/Relational Impedance Mismatch?
- What is the difference between EntityManager and EntityManagerFactory?
Answer to these questions is available in my YouTube shorts and Instagram reels. I am not sharing any answer here because goal is not to provide you questions and answers which you need to cram before interview, but to provide you idea that which question I have answered on which day. It will be always better to go through all questions at your own pace, understand my way of explaning and then create your own answer.
Answers have been explained in an easy way on my YouTube channel Abhishek Verma and on Instagram Abhishek Verma.
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