println("Welcome to the Scala worksheet")       //> Welcome to the Scala worksheet//(1 to 9)数组中的map方法向数组中放* 用foreach用于来循环 println _ 表示函数，把函数当做参数进行传递(1 to 9).map("*" * _).foreach(println _)        //> *//| **//| ***//| ****//| *****//| ******//| *******//| ********//| *********//过滤后被2整除的遍历  println也当做参数进行传递这就是高阶函数(1 to 9).filter(_ % 2 == 0) .foreach(println)   //> 2//| 4//| 6//| 8//_*_代表数组中两个数据相乘 也属于高阶函数println((1 to 9).reduceLeft(_ * _))             //> 362880//把字符串用空格分割在按照长度排序"Spark is the most exciting thing happening in big data today".split(" ").sortWith(_.length < _.length).foreach(println)//> is//| in//| the//| big//| most//| data//| Spark//| thing//| today//| exciting//| happening//ceil函数表示向上取值val fun = ceil _                               //> fun  : Double => Double = <function1>val num = 3.14                                 //> num  : Double = 3.14fun(num)                                       //> res0: Double = 4.0Array(3.14, 1.42, 2.0).map(fun)//fun函数当做函数传递   //> res1: Array[Double] = Array(4.0, 2.0, 2.0)//函数表示三的倍数val triple = (x: Double) => 3 * x             //> triple  : Double => Double = <function1>Array(3.14, 1.42, 2.0).map((x: Double) => 3 * x)//> res2: Array[Double] = Array(9.42, 4.26, 6.0)Array(3.14, 1.42, 2.0).map{ (x: Double) => 3 * x }//> res3: Array[Double] = Array(9.42, 4.26, 6.0)//定义高阶函数def high_order_functions(f: (Double) => Double) = f(0.25)//> high_order_functions: (f: Double => Double)Doubleprintln(high_order_functions(ceil _))         //> 1.0println(high_order_functions(sqrt _))         //> 0.5//函数相乘def mulBy(factor: Double) = (x: Double) => factor * x//> mulBy: (factor: Double)Double => Doubleval quintuple = mulBy(5)                      //> quintuple  : Double => Double = <function1>println(quintuple(20))                        //> 100.0//3的倍数解析println(high_order_functions((x: Double) => 3 * x))//> 0.75high_order_functions((x) => 3 * x)            //> res4: Double = 0.75high_order_functions(x => 3 * x)              //> res5: Double = 0.75
    println(high_order_functions(3 * _))          //> 0.75
    val fun2 = 3 * (_: Double)                    //> fun2  : Double => Double = <function1>val fun3: (Double) => Double = 3 * _          //> fun3  : Double => Double = <function1>

  var data = 0val frame = new JFrame("SAM Testing");val jButton = new JButton("Counter")jButton.addActionListener(new ActionListener {override def actionPerformed(event: ActionEvent) {data += 1println(data)}})//隐式函数就把一些函数定义，好比java中的函数定义模块-->这就可以隐式转换implicit def convertedAction(action: (ActionEvent) => Unit) = new ActionListener {override def actionPerformed(event: ActionEvent) { action(event) }}//这样是写代码的时候只关心业务逻辑，没有必要去编写没有关系的代码，直接写所需的结果  jButton.addActionListener((event: ActionEvent) => {data += 1; println(data)})//这跟java中的gui编程一样
    frame.setContentPane(jButton);   frame.pack();  frame.setVisible(true);  

    //curring颗粒度，就是把参数简化成一个参数进行操作，返回后把另外进行计算def multiple(x: Int, y: Int) = x * ydef multipleOne(x: Int) = (y: Int) => x * yprintln(multipleOne(6)(7))//可以把以上的计算方式该项为下面的方法def curring(x: Int)(y: Int) = x * yprintln(curring(10)(10))val a = Array("Hello", "Spark")val b = Array("hello", "spark")//比较两个变量的是否相等println(a.corresponds(b)(_.equalsIgnoreCase(_)))

  //模式匹配在java中用switch来表示，这里面限制不是很多,int,byte,char,shortval data =2data match {case 1 => println("First")case 2 => println("Second")case _ => println("Not Known Number")}//Scala中case中可以用条件函数也可以是函数，也可以传参数val result = data match {case i if i == 1 => "The First"case number if number ==2 => "The Second" + numbercase _ => "Not Known Number"}println(result)  "Spark !" foreach { c => println (c match {case ' ' => "space"case ch => "Char: " + ch})}