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Walkthrough - Kotlin Tour: Special Classes

Walkthrough - Kotlin Tour: Special Classes

In this lesson, we explored specialized class types in Kotlin, including Open classes for inheritance, Enum classes for constants, Sealed classes for restricted hierarchies, and Inline Value classes for performance.

Changes Made

Implementation

  • Created SpecialClasses.kt which implements:
    • Open Classes: Demonstrating inheritance using open and override with Transport and Auto.
    • Enum Classes: Using Color with custom properties (rgb) and functions.
    • Sealed Classes: A restricted hierarchy with Mammal, Human, and Cat.
    • Inline Value Classes: Using @JvmInline value class Email for type-safe performance.
    • Exercises:
      • DeliveryStatus (Sealed class) representing package states.
      • Status (Sealed class) with a nested Problem enum for error handling.
  • Updated App.java to execute these demonstrations.

Verification

  • Build: Successfully executed ./gradlew :app:assemble.
  • Logic: Verified that when expressions are exhaustive for sealed classes and that enum functions work as expected.

See the Step-by-Step Explanation for technical details.

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