Scala 学习笔记

 1 object func_exp {
 2   println("Welcome to the Scala worksheet")       //> Welcome to the Scala worksheet
 3   def hello(name: String): String = {
 4     s"Hello, ${name}"
 5     }                                             //> hello: (name: String)String
 6     
 7    hello("hadoop")                                //> res0: String = Hello, hadoop
 8    
 9    def hello2(name: String): String = {
10     s"Hello, ${name}"
11     }                                             //> hello2: (name: String)String
12     
13     
14     def add(x: Int, y: Double) = x * y            //> add: (x: Int, y: Double)Double
15     add(1,6)                                      //> res1: Double = 6.0
16     
17     
18     
19     val l = List("hadoop","java","scala")         //> l  : List[String] = List(hadoop, java, scala)
20     for(
21             s<-l
22     )println(s)                                   //> hadoop
23                                                   //| java
24                                                   //| scala
25                                                   
26    val xz = List("hadoop","java","scala")         //> xz  : List[String] = List(hadoop, java, scala)
27     for(
28             s<-l
29     if(s.length>4)
30     )println(s)                                   //> hadoop
31                                                   //| scala
32                                                   
33                                                   
34                                                   
35     val result_for = for {
36             s<-l
37             s1 = s.toUpperCase()
38             if(s1 != "")
39     }yield(s1)                                    //> result_for : List[String] = List(HADOOP, JAVA, SCALA)
40     
41     
42     
43     
44     val code = 4                                  //> code  : Int = 4
45     val rest_match = code match{
46             case 1 => "one"
47             case 2 => "two"
48             case _ => "other"
49 
50     }                                             //> rest_match  : String = other
51     
52     
53     val rest_try = try {
54             Integer.parseInt("dog")
55     } catch {
56             case _ => 0
57     }finally{
58             println("always be printed")
59     }                                             //> always be printed
60                                                   //| rest_try  : Int = 0
61 }