In Kotlin interfaces are very similar to Java interfaces, but we can also provide a default implementation for an interface member:
interface IEmployee{
var name : String //abstract property
fun doWork(){
//some default implementation
}
fun doBreak() //abstract
}
Default implementation allows us to add functionality to interfaces without breaking existing code, because default implementation is not required to be implemented:
class Tester (override var name : String) IEmployee {
override fun doBreak () {... }
}
We can inherit from interfaces that have a member with the same signature:
interface ITester{
fun doWork () {...}
}
class Tester (override var name : String) : ITester, IEmployee{
override fun doBreak() {
}
override fun doWork() {
super<ITester>.doWork()
super<IEmployee>.doWork()
}
}
miniguide 