Conditional Statements (if, else, switch)

  Loops (for, while, do-while)

  Break and Continue Statements

  Logical, Relational, and Arithmetic Operators

  Defining and Calling Methods

  Method Overloading and Recursion

  Static and Instance Methods

  Pass by Value vs Pass by Reference

  Classes and Objects

  Constructors and this Keyword

  Inheritance (extends keyword)

  Polymorphism (Method Overriding)

  Encapsulation and Abstraction

  Interfaces and Abstract Classes

  Introduction to Exceptions

  Try-Catch Blocks

  Throws and Finally

  Custom Exceptions

  One-Dimensional and Multi-Dimensional Arrays

  ArrayList, LinkedList, HashSet, HashMap

  Iterating through Collections

  Comparable and Comparator Interfaces

  Reading and Writing Files

  Working with Streams (Byte and Character Streams)

  Serialization and Deserialization

  Creating Threads using Thread Class and Runnable Interface

  Synchronization and Thread Safety

  Executor Framework

  Inter-Thread Communication