random和yield的使用

import scala.collection.mutable.ArrayBuffer
import scala.math.randomdef randomArray(n:Int):Array[Int]={val a = for(i <- 0 until n) yield (random * n).toInta.toArray
}

对数组方法的使用

def reorderArray(arr:Array[Int]):Array[Int]={val t = arr.toBufferfor(i <- 0 until (t.length,2) if i + 1 < t.length){val a = t(i)val b = t(i + 1)t.remove(i,2)t.insert(i,b)t.insert(i + 1,a)}t.toArray
}

def reorderArray(arr:Array[Int]):Array[Int]={val t = arr.toBufferval result = for(i <- 0 until t.length)yield if(i%2==0 && i + 1 < t.length)t(i + 1)else if(i%2==0 && i + 1 >= t.length)t(i)else t(i - 1)result.toArray
}

感觉代码有点丑也难读。需要优化。

//使用循环def reorderArray(arr:Array[Int]):Array[Int]={val a = ArrayBuffer[Int]()val b = ArrayBuffer[Int]()arr.foreach(arg => if(arg > 0) a += arg else b += arg)a ++= ba.toArray}
//使用filter
def reorderArray(arr:Array[Int]):Array[Int]={val a = arr.filter(_ > 0).map(1 * _)val b = arr.filter(_ <= 0).map(1 * _)val c = a.toBufferc ++= bc.toArray
}

def aveArray(arr:Array[Double]):Double={arr.sum/arr.length
}

def reverseArray(arr:Array[Int]):Array[Int]={arr.reverse
}

产出数组的代码就不编写了。去重只需要调用api即可

def distinctArray(arr:Array[Int]):Array[Int]={val t = arr.toBuffert.distinct.toArray
}

性能嘛，自己比较吧!

def removeArray(arr:Array[Int]):Array[Int]={val t = arr.toBufferval idx = ArrayBuffer[Int]()for(i <- 0 until t.length){if(t(i) < 0)idx += i}idx.remove(0)idx.reverseidx.foreach(t.remove(_))t.toArray
}

显示的都是中文时间，后续的过滤无法操作。只列出所有的时区

val t = for(i <- getAvailableIDs) yieldgetTimeZone(i).getDisplayName()

val flavors = SystemFlavorMap.getDefaultFlavorMap().asInstanceOf[SystemFlavorMap] 然后以DataFlavor.imageFlavor为参数调用getNativesForFlavor方法，以Scala缓冲保存返回值。 (为什么用这样一个晦涩难懂的类？因为在Java标准库中很难找到使用java.util.List的代码)

val flavors = SystemFlavorMap.getDefaultFlavorMap().asInstanceOf[SystemFlavorMap]
println(flavors.getNativesForFlavor(DataFlavor.imageFlavor).toArray.toBuffer.mkString(" | ")

Blog URL:http://www.ivanpig.com/blog/?p=461