SCALA常规练习B

package com.hengheng.scala

class Point(val x : Int, val y : Int) {
val isOriginal : Boolean = {
x == 0 && y == 0
}

}
class TalkPoint(x : Int, y : Int) extends Point(x, y) {
def talk() = {
println("My position is (" + x + "," + y + ")")
}
}
class HappyTalkPoint(x : Int, y : Int) extends TalkPoint(x, y) {
override def talk() {
println("I'am happy!")
super.talk()
}
}
abstract class Animal {
def walk(speed : Int)

def breathe() = {
println("Aninamal breathes.")
}
}
class Dog extends Animal {
override def walk(speed : Int) = {
println("Dog walks, speed is " + speed)
}
}
object Application{
def main(args : Array[String]) {
val p = new Point(0, 0)
println("point info(" + p.x + "," + p.y + ")")
println(p.isOriginal)
val pp = new TalkPoint(3,4)
pp.talk()
val ppp = new HappyTalkPoint(0, 0)
ppp.talk()
val d = new Dog()
d.walk(10)
d.breathe
}
}

　　输出：

point info(0,0)
true
My position is (3,4)
I'am happy!
My position is (0,0)
Dog walks, speed is 10
Aninamal breathes.