一 模式匹配

基础语法

Java

一般匹配类型是整数或字符串

int flag = 1
String res = ""
swich(flag){
     case 1 :
       res = "1";
       break;
     case 2 :
       res = "2";
       break;
     default :
       res = "3";
       break;
}

Scala

val op : Any = ops match {
      case "+" => a+b
      case "-" => a-b
      case "*" => a*b
      case "/" => a/b
      case _  => "没有该操作"  //默认
}

案例应用

 def ops(op:String,a:Int,b:Int): Any = op match {
      case "+" => a+b
      case "-" => a-b
      case "*" => a*b
      case "/" => a/b
      case _  => "没有该操作"  //默认
    }
println(ops("++",1,3))