Scala入門與進階（五）- 模式匹配

6.模式匹配

1.最基礎的模式匹配

Java: 對一個值進行條件判斷，返回針對不一樣的條件進行不一樣的處理

Scala:

變量 match {
case value1 =>代碼1,
case value2 =>代碼2,
...
case _ => 代碼N
}
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object MatchApp extends App {

val names = Array("zhangsan","lisi","wangwu")
val name = names(Random.nextInt(names.length))

name match {
case "zhangsan" => println("張三...")
case "lisi" => println("李四...")
case _ => println("真的不知道大家在說什麼")
}

}
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2.加條件進行匹配

3.Array模式匹配

def greeting(array:Array[String])={
array match{
case Array("zhangsan") => println("Hi zhangsan")
case Array(x,y) => println("Hi "+x+" , "+y)
case Array("zhangsan",_*) => println("Hi zhangsan and other friends")
case _ => println("Hi everybody")
}
}
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4.List模式匹配

5.類型匹配

def matchType(obj:Any)={
obj match {
case Int => println("Int")
case String => println("String")
case m:Map[_,_] => m.foreach(println)
case _ => println("other type")
}
}
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6.Scala異常處理

7.case class

class Person
case class CTO(name: String,floor:Int) extends Person
case class Employee(name: String,floor:Int) extends Person
case class Other(name:String) extends Person

def caseclassMatch(person: Person)={
person match{
case CTO(name,floor) => println("CTO name is "+name+", floor is "+floor)
case Employee(name,floor) => println("Employee name is "+name+", floor is "+floor)
case _ => println("other")
}
}
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