Abstract class: a half-built house — some walls exist with real code, some rooms are only marked abstract until a subclass finishes them. Interface: a checklist of behaviors — still no fields unless you cheat with properties in interfaces on newer JVM targets. In Kotlin you will lean on interfaces + data classes + sealed types often; abstract classes appear when you truly want shared stateful logic in a base.
Abstract class sketch
Content is available with subscription.
Get full access to all courses on the platform for one year with a single payment.
▼
Unlike other platforms that charge per course, here you get everything for one price, and after one year of use there will be no automatic charge for the following year.