Java, DSA and JavaScript Interview Questions

Programming Languages

  1. Difference Between Java and C# (C Sharp) 
  2. Difference Between Java and .Net (DotNet)
  3. Java vs Python: Difference Between Java and Python
  4. Difference Between React and React Native
  5. Java vs Kotlin
  6. Java vs Core Java
  7. Difference Between Java and C++ (Java vs C++)
  8. Java vs JavaScript

Core Java

  1. JDK vs JRE vs JVM
  2. instance initializer vs static initializer block in java
  3. String vs StringBuffer in Java
  4. String vs StringBuilder in Java
  5. StringBuffer vs StringBuilder
  6. HTTP vs HTTPS
  7. equals() vs compareTo() methods
  8. wait vs sleep in Java
  9. StackOverflowError Vs OutOfMemoryError In Java
  10. static vs non-static nested class in Java
  11. super vs this keyword in Java
  12. break vs continue in Java
  13. Class.forName() vs ClassLoader.loadClass() in Java
  14. transient vs volatile in Java
  15. Comparable vs Comparator in Java
  16. Static Variable vs Instance Variable
  17. Shallow Copy vs Deep Copy in Java
  18. Static Block vs Static Method in Java
  19. Default Constructor vs Parameterized Constructor in Java
  20. GET vs POST Methods
  21. Java Bean vs POJO (Plain Old Java Object)
  22. Local Variable vs Global Variable in Java
  23. Constructor vs Method in Java
  24. Early (Static) Binding vs Late (Dynamic) Binding
  25. Concrete Class vs Abstract Class in Java
  26. Abstract Class vs Interface
  27. == operator vs equals method in Java
  28. Errors vs Exceptions
  29. Checked Exceptions vs Unchecked Exceptions
  30. Process vs Thread
  31. Method Overloading vs Method Overriding

DS and Algorithms

  1. Stack vs Linked List
  2. Stack vs Queue
  3. Stack vs Heap
  4. Tree vs Linked List in Java
  5. Tree vs Graph
  6. Tree vs Binary Tree
  7. LinkedList vs ArrayDeque
  8. LinkedList vs Array
  9. LinkedList vs Doubly LinkedList
  10. Queue vs Deque
  11. Bubble Sort vs Selection Sort
  12. Linear Search vs Interpolation Search
  13. Topological Sort vs Depth-First Search (DFS)
  14. Fibonacci Heap vs Binary Heap
  15. Inorder Traversal vs Preorder Traversal
  16. Bubble Sort vs Insertion Sort
  17. B-trees vs B+ trees
  18. AVL trees vs Red-Black trees
  19. Min-Heap vs Max-Heap
  20. Merge Sort vs Quick Sort
  21. Priority Queue vs Normal Queue
  22. Linear Search vs Binary Search
  23. Heap vs Binary Search Tree (BST)
  24. Depth-First Search (DFS) vs Breadth-First Search (BFS)
  25. Binary Tree vs Binary Search Tree (BST)


  1. map() vs flatMap() in Java
  2. Collections vs Streams
  3. ArrayList vs Vector
  4. Iterator vs ListIterator
  5. HashMap vs HashTable
  6. HashSet vs HashMap
  7. Array vs ArrayList
  8. Fail-Fast Iterators vs Fail-Safe Iterators
  9. HashMap vs ConcurrentHashMap
  10. LinkedList vs ArrayDeque
  11. LinkedList vs Array
  12. LinkedList vs Doubly LinkedList
  13. Enum vs EnumSet in Java
  14. HashMap vs TreeMap in Java
  15. Synchronized Collections vs Concurrent Collections

Spring and Hibernate

  1. Spring MVC vs Spring Boot
  2. Hibernate vs JDBC
  3. Spring vs Hibernate
  4. JPA vs Spring Data JPA
  5. Spring vs Spring Boot


  1. Difference Between let vs var vs const JavaScript
  2. Differences Between == and === in JavaScript
  3. null vs undefined in JavaScript
  4. NaN vs undefined in JavaScript
  5. Arrow functions vs Regular functions in JavaScript
  6. localStorage vs sessionStorage in JavaScript