Classes and Objects

Attributes and Methods in Class

Constructors and destructors

Modifiers in Java

Encapsulation

Inheritance (Single, Multilevel, Hierarchical)

This, super and final keywords

Polymorphism

Inner Class in Java

Abstraction (Abstract classes and methods)

Interfaces

Enums

Packages

Introduction to Collections

List, Set, Map, Queue interfaces

ArrayList, LinkedList, HashSet, HashMap etc.

Iterators and for-each loop

Comparable and Comparator interfaces

Utility classes (Collections and Arrays)

Types of exceptions (checked and unchecked)

Custom exceptions

try-catch block with multiple catches

Nested try blocks and finally clause

Throwing exceptions using throw

Introduction to Threads

Creating threads using Thread class and Runnable interface

Thread lifecycle and states

Thread synchronization

Inter-thread communication

Daemon threads and thread priority

Lambda expressions

Default and static methods in interfaces