//constructor call
val file=File("file.txt")
class File(val fileName:String)
//class
class User
//public 类型class
open class User1
//optional Arguments in Constuctors
class User2(var name:String,var lastName :String="")
//class properties set method
class Document{
var id:String="00x"
set(value){
if(value.isNotEmpty()) field=value
}
}
//abstract class
abstract class Document1 {
abstract fun calculateSize():Int
}
class Photo:Document1(){
override fun calculateSize():Int{
return 0
}
}
//singleton
object Document4{
}
//method extensions
fun ByteArray.toHex():String{
return ""
}
val dummyData=byteArrayOf()
val hexValue=dummyData.toHex()
// inner class
class Document11{
inner class InnerClass
}
//nested class
class Document12{
class InnerClass
}
//interface
interface PrintTable{
fun print()
}
class Documentt:PrintTable{
override fun print(){}
}