← Exit to Module 7: Advanced Object-Oriented Concepts lessons
Module progress · 0%Lesson · 16 min
Module 7: Advanced Object-Oriented Concepts
Lesson focusCasting, instanceof, and Pattern Matching
Use safe casting techniques, pattern matching, and `sealed` classes to enforce invariants.
01 · 25 minDesigning Robust Inheritance HierarchiesLocked02 · 20 minMethod Overriding Rules & ContractsLocked03 · 15 minDeep Dive: The super KeywordLocked04 · 22 minAbstract Classes vs InterfacesLocked05 · 18 minMultiple Inheritance Through InterfacesLocked06 · 14 minDefault & Static Interface MethodsLocked07 · 12 minMarker Interfaces & Metadata AlternativesLocked08 · 20 minAdvanced Polymorphism PatternsLocked09 · 16 minCasting, instanceof, and Pattern MatchingLocked10 · 15 minComposition vs InheritanceLocked11 · 30 minMini-Project: Shape HierarchyLocked
Prefer instanceof pattern matching (if (obj instanceof Order order)) to reduce explicit casts and improve clarity.
Downcasting couples code to specific subclasses; wrap behaviors in polymorphic methods instead when possible.
Sealed classes (Java 17+) restrict which classes may extend a base type, enabling exhaustive switch expressions.