Most Asked Core Java Interview Questions and Answers
  • Why Java is not 100% Object Oriented
  • Is Java Pass by value or Pass by reference
  • What is Covariant return type in Java ?
  • What is Equals and Hash Code contract ?
  • Why Pointers are not used in Java ?
  • What is JIT compiler in Java ?
  • Why String is immutable in Java ?
  • What is Marker Interface ?
  • Can you override a private or static method in Java ?
  • Does finally always execute in Java ?
  • How to break Singleton Design pattern in Java ?
  • What methods does Object class have ?
  • How to make class Immutable ?
  • How to make a class Singleton ?
  • Explain the Collection Hierarchy
  • What is List interface in Java ?
  • What is set Interface in Java ?
  • What is Queue Interface in Java ?
  • What is Map Interface in Java ?
  • Why map does not extend Collection Interface ?
  • What is the difference between fail fast and fail safe Iterator ?
  • What is Blocking Queue ?
  • Difference between synchronized collection and concurrent collection
  • Explain Internal working of Hashmap
Additional Content
  • Why Java 8 was introduced ?
  • What are the advantages of Java 8 ?
  • What is Lambda expression ?