Scala实现两个对象的比较

// 随机定义一个方法
class XiaoHei(val name:String, val age:Int) {
  // 重写toString方法
  override def toString:String = s"name:${name}, age:${age}"
}

object Scala4 {
  // 定义隐式对象
  implicit object Order extends Ordering[XiaoHei]{
    // 重写（自定义）compare方法
    override def compare(x:XiaoHei, y:XiaoHei): Int = x.age -y.age
  }
}

object OderingDemo {
  // 定义比较方法
  def choose(t1:XiaoHei, t2:XiaoHei): XiaoHei = {
    // 引入隐式对象
    import Scala4.Order
    if (Ordering[XiaoHei].compare(t1, t2) > 0) t1 else t2
  }
  // 主方法
  def main(args:Array[String]): Unit = {
    val s1 = new XiaoHei("小黑",10)
    val s2 = new XiaoHei("小白", age = 12)
    println(choose(s1,s2))
  }
}

// 定义泛型类，接受参数为Comparable的实现类
class ChooseClass[T <: Comparable[T]] {
  // choose方法实现Comparable实现类的具体比较
  def choose(t1:T, t2:T): T = {
    if (t1.compareTo(t2) >0) t1 else t2
  }
}

// 定义comparable的实现类，实现compareTo方法
class CompareClass(val name:String) extends Comparable[CompareClass] {
  override def toString:String = this.name
  override def compareTo(o: CompareClass): Int = this.name.compareTo(o.name)
}

// 测试类
object Test {
  def main(args:Array[String]): Unit = {
    val choose1 = new ChooseClass[Integer]
    println(choose1.choose(100,200))
    val choose2 = new ChooseClass[CompareClass]()
    println(choose2.choose(new CompareClass("小黑"),new CompareClass("小白")))
  }
}