Scala这一路 之 应用-Trait 入门篇

摘要：Scala 中Trait 相当于Java语言中的Interface （接口），不同的是Trait可以定义属性与方法实现(ps:下一节深入篇会介绍)。相比较来说比接口还要强大些。

#保存文件 Equal.scala
trait Equal{
	def isEqual(x:Any):Boolean
	def isNotEqual(x:Any): Boolean = !isEqual(x)
}

class Point(xc: Int, yc: Int) extends Equal {
  var x: Int = xc
  var y: Int = yc
  def isEqual(obj: Any) =
    obj.isInstanceOf[Point] &&
    obj.asInstanceOf[Point].x == x
}

object Test {
   def main(args: Array[String]) {
      val p1 = new Point(2, 3)
      val p2 = new Point(2, 4)
      val p3 = new Point(3, 3)

      println(p1.isEqual(p2))
      println(p1.isEqual(p3))
      println(p1.isEqual(2))
   }
}


#执行文件
scala> :load Equal.scala
:load Equal.scala
Loading Equal.scala...
defined trait Equal
defined class Point
defined object Test

scala> Test.main(null)
Test.main(null)
true
false
false

~END