Learn
Practice
Newsletter
Resources
Animations
New
F
Toggle theme
0
F
0
Toggle menu
Sealed Classes
Last Updated: June 2, 2026
Low Priority
19 min read
Get Premium
Subscribe to unlock full access to all premium content
Subscribe Now
Reading Progress
0%
On this page
The Problem: Hierarchies Are Open by Default
The sealed and permits Keywords
Every Permitted Subtype Picks One of Three Modifie...
Sealed Interfaces
The Location Rule: Same Package or Same Module...
Exhaustive Switch Over a Sealed Type
Putting It Together: An Order Status Type
Common Mistakes
Sealed Classes vs Enums vs Regular Classes
Quiz
Vote/Request Content
Aa
Notes
Star
Complete
Ask AI
Exercise: Record Cla...
Notes
Star
Complete
Ask AI
Exercise: Sealed Cla...
