scala 入门demo

http://www.yiibai.com/scala/

/** * Created by Administrator on 2015/9/16. */object HelloWorld {   def main(args: Array[String]) {     println("laizi helloworld")  }}

/** * Created by Administrator on 2015/10/21. */object Collect {  def main(args: Array[String]) {    // Define List of integers.    val l = List(1,2,3,4)    println(l)    // Define a set.    var s = Set(1,3,5,7)    println(s)    // Define a map.    val m= Map("one" -> 1, "two" -> 2, "three" -> 3)    println(m.toString())    println(m)    // Create a tuple of two elements.    val t = (10, "Scala")    println(t)    // Define an option    val o:Option[Int] = Some(5)    println(o)  }}

object For {  def main(args: Array[String]) {    var a = 0;    val numList = List(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);    // for loop execution with a yield    var retVal = for {a <- numList                      if a != 3; if a < 8    } yield a    // Now print returned values using another loop.    for (a <- retVal) {      println("Value of a: " + a);    }  }}

class Person {  private var name=null;  var age=0;  protected var city=null;  protected def f() {    println("f")  }  def d() {    println("d")  }  def c() {    println("c")  }  def addInt( a:Int, b:Int ) : Int = {    var sum:Int = 0    sum = a + b    return sum  }}

import scala.util.control.Breaks/** * Created by wjh on 2015/10/21. */object Main {  def printMe( ) : Unit = {    println("Hello, Scala!")  }  def testBreak(){    var a = 0;    val numList = List(1,2,3,4,5,6,7,8,9,10);    val loop = new Breaks;    loop.breakable {      for( a <- numList){        println( "Value of a: " + a );        if( a == 4 ){          loop.break;        }      }    }    println( "After the loop" );  }  //基本语法  def  main (args: Array[String]) {    printMe();    println("xxx");    println("data")    println(Main.toString)    //可变变量    var myVar : String = "Foo可变变量"    myVar="fuck";    println(myVar)    //不可变变量    val myVal : String = "Foo不可变变量"    //myVal="fuck";    println(myVal)    var myVar1 = 10;    val myVal1 = "Hello, Scala!";    println(myVar1)    println(myVal1)    val (myVar2, myVar3) = Pair(40, "Foo多重任务")   // val (myVar2: Int, myVar3: String) = Pair(40, "Foo多重任务")    println(myVar2)    println(myVar3)    var person=new Person();    person.d();    person.c();    println(person.addInt(12,12));    //调用java方法    println(Math.PI)    println(Thread.currentThread().getName);    System.out.println("来自java")    var name=this.getClass.getSimpleName();    println(name)    var cls:String=this.getClass.getClassLoader.getClass.getName();    println(cls)    println(System.getProperties());    //http://www.yiibai.com/scala/scala_for_loop.html    var i=0;    for(i<- 0 to 15)    {      println("fuck"+i);    }    for( a <- 1 until 10){      println( "Value of a: " + a );    }    i=5;    while(i>0)    {      println("ok"+i);      i=i-1;    }    testBreak();  }  override def toString: String  =super.toString}

import java.io.{FileNotFoundException, FileReader, IOException}import java.util.Dateobject TestName {  def main(args: Array[String]) {    delayed(time());    printInt(b = 5, a = 7);    for (i <- 1 to 10)      println("Factorial of " + i + ": = " + factorial(i))    var palindrome = "Dot saw I was Tod";    var len = palindrome.length();    println("String Length is : " + len);    printStrings("Hello", "Scala", "Python");    println("Returned Value : " + addInt());    val str1: String = "Hello, "    val str2: String = "Scala!"    println("str1 + str2 = " + strcat(str1)(str2))    val date = new Date    log(date, "message1")    log(date, "message2")    Thread.sleep(1000)    log(date, "message3")    //迭代器    val it = Iterator(20, 40, 2, 50, 69, 90)    // println(it.size)    //println(it.length)    // println(it.max)    //println(it.min)    while (it.hasNext) {      println(it.next())    }    try {      val f = new FileReader("input.txt")    } catch {      case ex: FileNotFoundException => {        println("Missing file exception")      }      case ex: IOException => {        println("IO Exception")      }    } finally {      println("Exiting finally...")    }  }  def time() = {    println("Getting time in nano seconds")    // System.nanoTime    System.currentTimeMillis()  }  def delayed(t: => Long) = {    println("In delayed method")    println("Param: " + t)    //调用    t;  }  def printInt(a: Int, b: Int) = {    println("Value of a : " + a);    println("Value of b : " + b);  }  //递归调用  def factorial(n: BigInt): BigInt = {    if (n <= 1)      1    else      n * factorial(n - 1)  }  //可变参数  def printStrings(args: String*) = {    var i: Int = 0;    for (arg <- args) {      println("Arg value[" + i + "] = " + arg);      i = i + 1;    }  }  //默认参数值  def addInt(a: Int = 5, b: Int = 7): Int = {    var sum: Int = 0    sum = a + b    return sum  }  def strcat(s1: String)(s2: String) = {    s1 + s2  }  def log(date: Date, message: String) = {    println(date + "----" + message)  }}

/** * Created by Administrator on 2015/10/21. */object TestObj {  class Yiibai(val xc: Int, val yc: Int) {    var x: Int = xc    var y: Int = yc    def move(dx: Int, dy: Int) {      x = x + dx      y = y + dy      println("Yiibai x location : " + x);      println("Yiibai y location : " + y);    }    //    override def toString(): String="x="+x+",y="+y    override def toString(): String = {      "x=" + x + ",y=" + y    }  }  class Location(override val xc: Int, override val yc: Int,                 val zc :Int) extends Yiibai(xc, yc){    var z: Int = zc    def move(dx: Int, dy: Int, dz: Int) {      x = x + dx      y = y + dy      z = z + dz      println ("Yiibai x location : " + x);      println ("Yiibai y location : " + y);      println ("Yiibai z location : " + z);    }    override def toString(): String = {      "x=" + x + ",y=" + y+",z="+z    }  }  def main(args: Array[String]) {    val pp = new Yiibai(10, 20);    pp.move(20, 20);    println(pp)    val loc = new Location(10, 20, 15);    // Move to a new location    loc.move(10, 10, 5);    println(loc)    printYiibai    def printYiibai{      println ("Yiibai x location : " + pp.x);      println ("Yiibai y location : " + pp.y);    }    //http://www.yiibai.com/scala/scala_pattern_matching.html    println(matchTest("two"))    println(matchTest("test"))    println(matchTest(1))    print("Please enter your input : " )    val line = Console.readLine    println("Thanks, you just typed: " + line)  }  //模式匹配  def matchTest(x: Any): Any = x match {    case 1 => "one"    case "two" => 2    case y: Int => "scala.Int"    case _ => "many"  }}

实例源码下载(右键保存图片，重命名为rar即可)：