01
ZeroToOneLearn. Code. Excel.
HomeLanguagesDSASystem DesignLow Level DesignRoadmapsAbout

Java Fundamentals

Progress: 225/225 chapters
Abstraction BasicsšŸ’¼
Abstract Classes
Abstract Methods
InterfacesšŸ’¼
Default Methods
Static Methods in Interfaces
Functional Interfaces
Marker Interfaces
Interface vs Abstract ClassšŸ’¼
Languages/Java/Abstraction

Abstraction

9 Topics•9 Completed•
100%
1

Abstraction Basics

Hiding implementation details

Core OOP principle
2

Abstract Classes

Classes that cannot be instantiated

3

Abstract Methods

Methods without implementation

4

Interfaces

Pure abstraction with interface keyword

Interface vs Abstract class
5

Default Methods

Interface methods with implementation (Java 8+)

6

Static Methods in Interfaces

Static methods in interfaces (Java 8+)

7

Functional Interfaces

Interfaces with single abstract method

8

Marker Interfaces

Interfaces without methods

9

Interface vs Abstract Class

When to use which

Very common interview question
Back to All Chapters
01
ZeroToOne

Learn. Code. Excel.

Learn

  • Languages
  • DSA
  • System Design
  • Low Level Design

Resources

  • Roadmaps
  • About

Connect

GitHub

Ā© 2026 ZeroToOneAlgo. All rights reserved.