6.模式匹配

1.最基础的模式匹配

Java: 对一个值进行条件判断，返回针对不同的条件进行不同的处理

Scala:

变量 match {
case value1 =>代码1,
case value2 =>代码2,
...
case _ => 代码N
}

object MatchApp extends App {

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

name match {
case "zhangsan" => println("张三...")
case "lisi" => println("李四...")
case _ => println("真的不知道你们在说什么")
}

}

2.加条件进行匹配

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")
}
}

4.List模式匹配

image.png

5.类型匹配

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

6.Scala异常处理

image.png

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")
}
}