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Refer to Scala Installation: http://www.lupaworld.com/thread-970271-1-1.html The following command installs the default Scala version sudo apt-get install Scala If you want to install a specific version, follow these steps: 1) Download Scala compression packwget http://downloads.typesafe.com

In the previous section, a Scala class was created, and if there are no more methods, the definition of the Scala class can be simpler, take a look at the following definition of the CreditCard class: class CreditCard (Val Number:int, var creditlimit:int)Yes, the definition of the class is completed in one line and no curly braces are required.Because Scala is al

(Var age:int) { ifelse age }7. Write a person class whose main constructor accepts a string that contains the name, space, and last name, such as new person ("Fred Smith"). Provides read-only properties FirstName and LastName. Should the main constructor parameter be a var,val or a normal parameter? Why?Val, if it is Var, the corresponding string has get and set methods, because only provide read-only properties FirstName and LastName, cannot be assigned repeatedly.8. Create a car class that c

( "* (maxlength- Key.length)) Print ( | ") println (props (key))}}} 8. Write a function Minmax (Values:array[int]) to return the duality of the minimum and maximum values in the array def Minmax (Values:array[int]) = { (values.max,values.min) }9. Write a function iteqgt (Values:array[int],v:int) that returns the number of less than V, equal to V, and greater than V in the array, requiring three values to be returned together def iteqgt (values:array[int],v:int) = { var a,b,c=0 for

part the results are aggregated together.coll.par.sumYou can apply par parallel for loop to the collection you want to traversefor(i 0100" ")In the For/yield cycle, the results are assembled in turn:for(i 0100yield" "Note Here whether the variable is a shared variable or a local variable within the loop:var0for (c if201} // error* * Note: The type of parallel collection returned by the **par method is a type that extends from Parseq, Parset, or parmap traits, all of which are subtypes of parit

node and its descendants. valnew RewriteRule { overridedefmatch { case"ol") }}After that, you can use the following command to transform an XML tree:val transformed = new RuleTransformer(rule1).transform(root)You can give multiple rules in the Ruletransormer constructor:val transformer = new RuleTransformer(rule1, rule2, rule3)Loading and savingTo load an XML document from a file, call the LoadFile method of the XML object:import scala.xml.XMLval root = XML.loadFile("myfil

Reader { type Contents = String def read(fileName: String) "UTF-8").mkString}class ImageReader extends Reader { type Contents = BufferedImage def read(fileName: String) = ImageIO.read(new File(fileName))}Another example: trait Reader[C]{ defRead (file:string): C} class stringreader extends Reader[String] { defRead (filename:string) = Source.fromfile (FileName,"UTF-8"). Mkstring} class imagereader extends Reader[bufferdimage] { defRead (filename:string) = Imageio.read (NewF

(args:array[string]): Unit = { breakable { for (I Scala for derivation, returns a vector collection Vector (1, 2, 3, 4, 5, 6, 7, 8, 9, ten) val a = for (I The named parameter of the Scala function def decorate (atr:string, left:string = "[", right:string = "]") = {left + ATR + right }decorate ("Hello" , right = ">>>]")Scala variable

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Learn Spark 2.0 (new features, real projects, pure Scala language development, CDH5.7)Share the network disk download--https://pan.baidu.com/s/1c2f9zo0 password: pzx9Spark entered the 2.0 era, introducing many excellent features, improved performance, and more user-friendly APIs. In the "unified programming" is very impressive, the implementation of offline computing and Flow computing API unification, the

) println (Card.H) println (CARD.F) }7. Implement a function to check if the color of a card is red extends enumeration with app{ = Value ("?" ) = Value ("?" ) = Value ("?" ) = Value ("?" ) def color (c:card.value) { if(c = = CARD.M | | c = = card.t) print ("Black") Else print ("Red") } Color (Card.H)}8. Write an enumeration that describes the 8 corners of an RGB cube. ID uses color values (for example: Red is 0xff0000) extends enumeration with app{ = value

This is a creation in Article, where the information may have evolved or changed. "Editor's note" according to data provided by PayScale, a payroll agency, the mastery of Scala,golang and Python languages and big data technologies such as Apache Spark can lead to the biggest salary increase. The author of this article is Serdar Yegulalp, the article is ITOM management platform in China OneAPM compiled rendering. Want a pay rise?

: T:Comparable[T])Type constraints allow you to define methods in generics that can be used only under certain conditions.class Pair[T](val first: T, val second: T){ def smaller(implicit ev: T if (first }Type ChangeExample:class Pair[+T] (val first: T, val second: T)Description: The plus sign means that the type is covariant with T, that is, it changes in the same direction as T.There can also be a type change in another direction.trait Friend[-T] { def befriend(someone: T)}

Learn Spark 2.0 (new features, real projects, pure Scala language development, CDH5.7)Share--https://pan.baidu.com/s/1jhvviai Password: SirkStarting from the basics, this course focuses on Spark 2.0, which is focused, concise and easy to understand, and is designed to be fast and flexible.The course is based on practical exercises, providing a complete and detailed source code for learners to

Rt. Package Com.scalalearn.scala.main/** * Learn Scala 02 exercises */Object LEARNSCALA02 {//1. If a number is positive, its signum is 1; if it is negative, SIGNU M is-1; if it is 0, then Signum is 0//write a function to calculate the value def execise1 (num:int): Int = {if (num > 0) 1 else if (num = = 0) 0 Else-1} 2. What is the value of an empty block expression. What is its type//value is (), the ty

passed in, you need to call Tobuffer for(I b) {A.remove (i) }}}9. Create a collection of time zones returned by Java.util.TimeZone.getAvailableIDs, judging by the condition that they are in the Americas, removing the "america/" prefix and sorting. import Scala.collection.mutable.ArrayBuffer import Scala.collection.JavaConversions.asScalaBufferobject hello{def main (args:array[ String]) = {var c = timeZoneName () C.forea CH (println)} def timezonename () = {val arr = Java.util.Time