کلاس های ابسترکت (abstract) در کاتلین

abstract class MyAbstractClass{ //abstract property abstract val t0: T //concrete property val t1: T = ... ... //abstract function abstract fun myAbstractFunction(t: T) //concrete function fun myFunction(t: T){ //Do Something Here... } ... }

abstract class Foo{ abstract val prop0: String abstract fun abstractSayHello() fun concreteSayHello(){ println("Hello from concrete function!") } } class Bar: Foo{ override val prop0 = "Hello from abstract property!" override fun abstractSayHello(){ println("Hello from Abstract function!") } } fun main(){ val bar = Bar() println(bar.prop0) bar.abstractSayHello() bar.concreteSayHello() }

abstract class MyBase{ //without abstract properties and (or) functions ... }

abstract class Shape(var color: String, var isFilled: Boolean = false){ val dateCreated = java.util.Date() override fun toString(): String{ return "Shape created at $dateCreated \ncolor is $color, \nisFilled? $isFilled" } } abstract class GeometricShape(color: String, isFilled: Boolean): Shape(color, isFilled){ abstract val area: Int abstract val perimeter: Int constructor(): this("White", false) override fun toString(): String{ return super.toString() + "\nArea is $area \nperimeter is $perimeter \nX is $x and Y is $y" } override fun equals(other: Any?): Boolean{ if(other !is GeometricShape) throw IllegalArgumentException("GeometricShape argument required") return other.area == this.area } } // تعریف کلاس دایره class Circle: GeometricShape{ var radius = 1 override val area get() = (radius * radius * PI).toInt() override val perimeter get() = (2 * radius * PI).toInt() constructor(radius: Int, color: String, isFilled: Boolean): super(color, isFilled){ this.radius = radius } constructor(): super() constructor(radius: Int): super(){ this.radius = radius } override fun toString(): String{ val fromGeometricShape = super.toString() return fromGeometricShape + "\nThe shape is Circle!" } } // تعریف کلاس مستطیل class Rectangle: GeometricShape{ var width = 1 var height = 1 override val area get() = width * height override val perimeter get() = (width + height) * 2 constructor(width: Int, height: Int, color: String, isFilled: Boolean): super(color, isFilled){ this.width = width this.height = height } constructor(): super() constructor(width: Int, height: Int): super(){ this.width = width this.height = height } fun isSquare(): Boolean = (width == height) override fun toString(): String{ val fromGeometricShape = super.toString() return fromGeometricShape + "\nThe shape is Rectangle!" } } fun main(){ val c = Circle(2) c.stroke = "Blue" val c1 = Circle(radius = 5, x = 1, y = 1, "Yellow", true) val rect = Rectangle(3 , 4) val rect1 = Rectangle(7, 7) println("$c") println("\n$c1") println("\n$rect") println("\n$rect1") println() println("Are c and rect equal? ${c.equals(rect)}") println("Are c1 and c equal? ${c1.equals(c)}" ) println() println("Is rect square? ${rect.isSquare()}") println("Is rect1 square? ${rect1.isSquare()}") }