Kotlin The interface already does that for you. With the interface, you can define a set of properties and methods, that the concrete types must follow and implement. Dependency Injection in Android with Dagger Spring Boot with Kotlin Directly using functions has the following advantages. In coroutines, a flow is a type that can emit multiple values sequentially, as opposed to suspend functions that return only a single value. Explain Interface in Kotlin | Kotlin Tutorial | Tutorials Link For example, interface MyInterface { var test: String // abstract property fun foo() // abstract method fun hello() = "Hello there" // method … Learn more about definitely non-nullable types in the KEEP.. Kotlin/JVM. Just like return types of functions are optionally specified, we do reserve a possibility that ... We will introduce an IDE checker for the Java code that is attempting to extend or implement a sealed Kotlin interface.