--- title: Object-Oriented Thinking Part Two | daily.dev description: A beginner-friendly introduction to OOP inheritance and polymorphism using Java. Covers class hierarchies, parent/child class relationships, the 'extends'... canonical: https://daily.dev/posts/object-oriented-thinking-part-two-elcsn1jut twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Object-Oriented Thinking Part Two | daily.dev og:description: A beginner-friendly introduction to OOP inheritance and polymorphism using Java. Covers class hierarchies, parent/child class relationships, the 'extends'... og:url: https://daily.dev/posts/object-oriented-thinking-part-two-elcsn1jut og:image: https://api.daily.dev/og/posts/ELCsn1Jut.png og:image:alt: Object-Oriented Thinking Part Two og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Object-Oriented Thinking Part Two **[Beej's Blog](https://daily.dev/sources/beej)** · 9 min read · 0 upvotes · 0 comments ## Summary A beginner-friendly introduction to OOP inheritance and polymorphism using Java. Covers class hierarchies, parent/child class relationships, the 'extends' keyword, calling superclass constructors with 'super()', and method overriding. Demonstrates how polymorphism allows an array of base-class references to dispatch the correct overridden method at runtime, using an Animal/Armadillo example throughout. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Fifty Shades of OOP](https://daily.dev/posts/fifty-shades-of-oop-o9n8jaztw) · Lobsters · 1 upvotes · 0 comments - [What Is Object-Oriented Programming \(OOP\)? 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