scala中的继承

package kangclass Animal2{  val num=3  val array=new Array[String](num)} /*class Person extends Animal2{//这种方式子类不能覆盖父类的成员   val num=5}*/class Person extends {//这是提前定义，子类能覆盖父类的成员  override val num=5} with Animal2//重写equals和hashcode方法class goods(val name:String,val salary:Int) {  final override def equals(other:Any)={    val a=other.asInstanceOf[goods]     if(a==null) false     else a.name==name&&a.salary==salary  }  final override def hashCode()=name.hashCode()+salary.hashCode()}object Scala_extends {  def main(args: Array[String]): Unit = {    val p=new Person()    println(p.array.length)  }}