Java Interfaces Deep Dive | Default Methods, Functional, Marker Interfaces | Java Full Course #24

In this video, we take a complete deep dive into Java Interfaces, not just what they are, but WHY they exist and HOW they actually work internally. If you’ve been memorizing “interfaces are used for abstraction” without truly understanding it, this video will completely change your perspective. We start from first thought principles and build everything step by step: What problem interfaces solve Difference between abstract class vs interface How Java achieves multiple inheritance using interfaces Default methods and why they were introduced (Java 8) Static methods inside interfaces Functional interfaces and lambda connection Marker interfaces (Cloneable, Serializable, RandomAccess) Real-world use cases and design thinking Prerequisite: Basic understanding of classes and OOP Why Learn Java? Java is one of the most powerful and widely used programming languages in the world. It is used in: Backend development Enterprise applications Android development Banking systems Large-scale distributed systems If you want to master Data Structures, Spring Boot, Microservices, or System Design, Java fundamentals are essential. Join Coder Army Whatsapp Group: https://whatsapp.com/channel/0029Va6H... Join System Design Whatsapp Group: https://whatsapp.com/channel/0029VbBF... Code and Notes: Github : https://github.com/adityatandon15/Jav... We offer paid course on Dsa, web development, blockchain, system design and GenAI. Join our Paid Course: https://strikes.in/ Coder Army: https://coderarmy.in/#home Coder Army app: https://play.google.com/store/apps/de... Connect with Aditya Tandon Instagram :   / adityatandon2   LinkedIn :   / adityatandon2   Twitter : https://x.com/adityatandon02 Timestamps: java interfaces, java interface tutorial, java interfaces explained, java interface vs abstract class, java default methods, java static methods interface, functional interface java, marker interface java, cloneable serializable randomaccess, java oop concepts, java full course, java for beginners ,java advanced concepts, learn java, java interview questions, java abstraction, java 8 features