risc-v开发基础 Scala match表达式 ---(8)

joe

scala match表达式
scala中的match表达式类似java中的switch语句，但功能比java中switch更强大。
java的switch case中只能用数字或常量，先来看看scala match的一个应用例子：

def greeting1(arg:String) {
  arg match {
    case "joe" => println("joe")
    case a=>println("variable value is "+a)
    case _ => println("not known")
  }
}
def greeting2(arg:Array[String]) {
  arg match {
    case Array("joe") => println("hello joe")
    case Array(a1,a2,a3) => println("hello "+a1 +","+a2+","+a3)
    case Array("joe",_*) => println("hello joe and everyone")
    case _ => println("hi")
  }
}
greeting1("joe") //joe
greeting1("jack") //variable value is jack
greeting1("someone") //variable value is someone
greeting2(Array("joe")) //hello joe
greeting2(Array("zs","li","wu","zl")) //hi
greeting2(Array("joe","rose")) //hello joe and everyone
greeting2(Array("tom","jack")) //hi
greeting2(Array("mick","tom","marry")) //hello mick,tom,marry