scala book

Demonstrates value functions, anonymous functions, closures ...Other specific applications, but also in the production of it.This is over. Other Sam,curry, higher-order functions, sets, generics, implicit classes: These, or find a special book to get a deeper understanding of ...C:\users\hengheng>scalawelcome to Scala version 2.11.6 (Java HotSpot (TM) 64-bit Server VM, Java 1.6.0_43). Type in expressions to

emails.SYSTEM.OUT.PRINTLN ("Prediction for positive test example:" + model.predict (postestexample));SYSTEM.OUT.PRINTLN ("Prediction for negative Test example:" + model.predict (negtestexample));Sc.stop ();}} Scala program Import Org.apache.spark.mllib.classification.LogisticRegressionWithSGDImport Org.apache.spark.mllib.feature.HashingTFImport Org.apache.spark.mllib.regression.LabeledPointImport Org.apache.spark. {sparkconf

Map Construction Map Immutable: Val map = map ("sa"-> 1, "S"-> 2)Map ("sa") = 3 // Error Val emptymap = new scala. collection. Immutable. hashmap [String, int] Variable: Val MAP2 = scala. collection. mutable. Map ("sa"-> 2)MAP2 ("sa") = 3 Val emptymap = new scala. collection. mutable. hashmap [String, int] Note:-> used to create tuples, "sa"-> 1 ("sa", 1) Initial

Install Scala 2.10.x in Ubuntu The default scala version on Ubuntu 14.04.1 LTS is 2.9, while the latest spark-1.3 requires the lowest version of scala 2.10.x, first, use apt-get remove scala to clear old scala versions on the machine. Download the http://www.scala-lang.org/

Mainly from the Coursera course "functional programming Principles in Scala"by Professor Martin Odersky, the inventor of the Scala language. 3. Data and Abstraction3.1 Class hierarchiesThis set of subtitles is out -,- of sync, listening to a little effort!The concept of a class is similar to that of other languages, such as base class, subclass, and parent class. In

Scala list faq:how do I add elements to a scala list?This was actually a trick question, because you can ' t add elements to a scalalist; It's an immutable data structure, like a Java String .prepending elements to Scala ListsOne thing you can does when working with a Scala was to List create a new from an List existin

Scala 学习One: Environment configurationScale official website address: http://scala-ide.org/download/sdk.html1: Install Java JDK2: Install Scala3: Install the Scala integrated IDESecond: Start the Scala learning journeyHello Scala Demo1: Create a new

We know that the IDE has a number of selected versions for development. As most of us often use is as follows.Eclipse * VersionEclipse * DownloadAnd we know that for the Scala development of Spark, there's a specially designed eclipse for it,Scala IDE for Eclipse　　1. Scala IDE for eclipse downloadhttp://scala-ide.org/

(Environment: Jdk1.7,scala plug-in scala-2.1.1.2-site.zip)1: Download Scala pluginHttp://download.scala-ide.org/sdk/helium/e38/scala211/stable/site 2: Unzip to LocalCopy all of the jar packages from the two files to the folder in the installation directory for Eclipse three: Restart Eclipse this will prompt you to have the plugin not enabled, click OK Four: Creat

Pattern matching using extractor: When an instance of a class is followed by parentheses using a list of 0 or more parameters, the compiler invokes the applied method on that instance. We can define both objects and classes. As mentioned above, the purpose of the Unapply method is to extract a particular value from what we are looking for. It operates in the opposite way as apply. An extract object that compares the Unapply method in a matching statement is automatically executed, as follows: Ob

Overview In short, implicit conversions are: When a Scala compiler does a type match, if the appropriate candidate is not found, implicit conversion provides another way to tell the compiler how to convert the current type to the expected type. The source of this article: http://blog.csdn.net/bluishglc/article/details/50866314 is strictly prohibited in any form of reprint, otherwise will entrust CSDN official maintenance rights and interests. Implici

how to rely on Scala's language features for high-force dependency injection What is dependency injection.Object is an abridged unit in the object-oriented world, and dependency injection groups the objects together. The simplest way to look at it is to inject the dependency into the object through a constructor or setter method.If we use the appropriate container, we can also extract the dependencies of each component of the system into the configuration file or configuration code, and inject

Implicit is a very important feature in Scala and has been thinking about it as much as Java before starting to learn Scala, but it's not as easy to see some of Scala's source code as it is, so I'm going to write a few articles to explain the features of Scala that are different from Java. Implicit, let's get started. In my opinion, what implicit do is also the m

ObjectiveFirst of all, we want to emphasize one important thing at the outset: Scala's pattern matching occurs but is not limited to the match case statement block, which is one of the key factors that Scala pattern matching is important and useful! We will discuss this in detail in the latter part of the article.Types of pattern matchingThere are several types of pattern matching in Scala: Wildcar

Knowledge Points: 1. Simple class and no parameter method class Counter { private// must initialize field // method default is public def Current () = value}In Scala, a class does not declare that a Public,scala source file can contain multiple classes, all of which have common visibility. New // or New Counter () mycounter.increment () println (Mycounter.current ())Call the no parameter method, you c

1. Pattern matching is much more powerful than switch case in Java, in addition to matching values, types, collections, and so on, the most common case class matches, and Master.scala has a large number of pattern matches.Case "_" means an experience that does not satisfy all of the above scenarios, for example:def bigdata (data:string) {Data match{Case "Spack" =>PRINTLN ("WOW!!!")Case "Hadoop" =>println ("OK")Case _=>println ("sorry")}}Bigdata ("spack")//WOW!!!You can add conditional judgment t

1. Install JDK 2. Install Scala Download the scala program at http://scala-lang.org/ Wget http://scala-lang.org/files/archive/scala-2.10.4.tgz Tar-zxvf scala-2.10.4.tgz-C/OPT Ln-S/opt/sca