scala in depth

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

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

Come from:http://lidrema.blog.163.com/blog/static/209702148201461145859142/Scala: A Java-like programming. Integrates object-oriented (object-oriented) programming and functional (functional programming) programming features to develop multi-core concurrency models and cloud computing (parallelism for Mulicore and cloud Comp uting). Bibliography: "Learn Scala", Author:horstmannbefore installing the

Use Scala to build Spring boot framework 1. Objective Spring boot is the most popular web framework on the Java development platform. Scala is a static type of functional programming language that runs on the JVM. The Big data processing spark framework is developed in the Scala language. This example integrates the Spring boot framework i

map4. Sorted MappingsAn immutable tree map is obtained as follows: Val scores4 = Scala.collection.immutable.SortedMap ("Alice", "Bob", 7, "Cindy", 9)For variable tree mappings, the closest option is to use Java's treemap.If all keys are accessed in the order in which they are inserted, Linkedhashmap is used. Val months = Scala.collection.mutable.LinkedHashMap ("January", 1, "February", "2", "March", 3, "April", 4, 5,...)5. Interoperability with JavaTranslating Java mappings into a

Scala as a functional programming language, to the students accustomed to the instruction programming language, will not be used to, here in addition to the way of thinking, there are grammatical aspects, such as underscore (underline) will appear in a variety of occasions, so that beginners are quite puzzled, today to summarize the next Scala The usage of the underline.1. Type of existence: Existentialtype

Scala 24-point game (1): expression computing (1) Scala 24-point game (2): expression computing (2) Scala 24-point game (3): expression computing (3) Scala twenty-four point game (4): One of the algorithms Scala game (5): List Introduction

　　First, prefaceLearn Scala's methods and then learn about object in ScalaSecond, ObjectThere are two meanings of object in Scala, in Java, which represents an instance of a class, and in Scala it's a keyword, and this article will first look at object as an instance of a class, showing how to convert objects from one type to another. We'll show you how to create a singleton, and there's a package object in

Eclipse is a very useful development tool, and the kids ' shoes that are familiar with it should know that it is not only the most commonly used Android development tool , but also the most common Java development tool. Since eclipse is so important, the small part of this article will be together with you to pick up the knowledge of building a Scala development environment in Eclipse, interested children shoes can come together to see.1 ,

Call-by-name and Call-by-value in Scala Var/def/val/lazy Valdef: Similar to every assignment, if you define a function with Def, you regain a function each time, doing call-by-name operations. Val: Get once and execute immediately, and no longer be modified during the life cycle, using the call-by-value operation. var: can be assigned again in the lifecycle lazy Val: Lazy execution, which is assignment (binding), is not performed until it is needed E

Scala learning document directory 1. Array 2. List 3. Map 4. Break 5. If else 6. 7. foreach 8. Option 9. tuple 10. Code conventions 11. Request to accept array or array content 12. Array usage 1) Scala Definition General Definition: Val array1 = array [String] ("str1", "str2 ") Array of specific length: Val array2 = new array [list [int] (Leng) 2) The array cannot be extended. Therefore, you can define arra

First, REPLThe Scala interpreter reads an expression, evaluates it, prints it out, and then continues to read the next expression. This process is called a read-print-loop, or REPL.Technically speaking, the Scala program is not an interpreter. What actually happens is that the content you enter is quickly compiled into bytecode, which is then handed to the Java Virtual machine for execution. Because of this

This is a creation in Article, where the information may have evolved or changed. Format conversion Classes category Python Java Scala Go Excel XLWT/XLRD, Xlsxwriter Poi - - Pdf PyPDF2 Apache FOP - - Csv Csvkit, Tablib - - - XML parsing Beautifulsoup/bs4 - - - Json - Jackson Json4s, Spr