Scala简单的例子

AnonymousFunc类如下所示：

package com.test.app

object AnonymousFunc {
  def adder(m: Int, n: Int) = m + n //更简单的写法

  def hello(x: Int) = x + 1 //简单的写法

  val add2 = adder(2, _: Int) //_表示占位符

  def multiply(m: Int)(n: Int): Int = m * n //优雅的写法

  def main(args: Array[String]) {
    println(add2(3))

    println(multiply(2)(3))

    val timesTwo = multiply(2)(_)
    println(timesTwo(3))

    var brand: String = "HP"  //命名规则类似于JAVA

    val color: String = if (brand == "TI") {
      "blue"
    } else if (brand == "HP") {
      "black"
    } else {
      "white"
    }

    println(color);
    
  }

}

PrintlnTest：

package com.test.app

object PrintlnTest {
  def main(args: Array[String]) {
    val array = Array(0, 1, 2, 3, 4, 5)

    array.foreach(i => print(i))
    println()
    array.foreach(print(_))
    println()
    array.foreach(print)
    println()
    for (i <- 0 until 5) {
      print(i)
    }
    println()
    for (i <- 0 to 5) {
      print(i)
    }

    println()

    val map = Map(0 -> 0, 1 -> 1, 2 -> 2, 3 -> 3, 4 -> 4, 5 -> 5)
    map.foreach {
      case (key, value) => {
        println("key:" + key + " value:" + value)
      }
    }

    val array1 = Array(0, 1, 2, 3, 4, 5)
    val array2 = Array(6, 7, 8, 9)
    val array3 = array1 ++ array2

    /**
     * drop(n) 移除前n个元素
     * take(n) 获取前n个元素
     * filter(condition) 获取指定condition的元素
     */
    //array3.foreach(println)
    array3.take(3).foreach(println)
    // array3.drop(1).foreach(println)
    //  array3.filter(_ != 1).foreach(println)

    /**
     * += 添加元素
     * ++ 合并集合
     */
  }
}

HelloScala：

package com.test.app

object HelloScala {

  def main(args: Array[String]) {
   //前10个数
    var i = 0;
    val rt =
      for (
        e <- ('a' to 'z') if { i = i + 1; i <= 10 }
      ) printf("%d:\t%s\n", i, e)
  
      
      //或者如下：
      ('a' to 'z').slice(0,10).foreach(println)
  
      //1 to 100 和小于1000的数
      var (n,sum)=(0,0); 
        for(i<-0 to 100 if (sum+i<1000)) { n=i; sum+=i }
  }

}

ScalaObject：

package com.test.app

object ScalaObject {
  //Map
  val colors = Map("red" -> 0xFF0000,
						    "turquoise" -> 0x00FFFF,
						    "black" -> 0x000000,
						    "orange" -> 0xFF8040,
						    "brown" -> 0x804000)

						    
  //match case: 相当于swich case
  def main(args: Array[String]) {
    println("Hello, world! " + args.toList)

    for (name <- args) println(
      colors.get(name) match {
        case Some(code) =>
          name + " has code: " + code
        case None =>
          "Unknown color: " + name
      })
      
      colors.get("red")
      
  }

}