scala programming tutorial

Package Com.leegh.parameterization/*** @author Guohui Li*/Because breathe returns This,scala the return type is inferred as animal, and because animal has no eat methodClass Animal {def breathe = this}Class Cat extends Animal {def eat = this}Class Animal {def Breathe:this.type = this}Class Cat extends Animal {def eat:this.type = this}Object Singleton_types {def main (args:array[string]): Unit = {Val cat = new CatCat.breathe.eat}}Report:This blog descr

Package Com.leegh.actorImport Scala.actors.Actor/*** @author Guohui Li*/Object First_actor extends Actor {Def Act () {for (I println ("Step:" + i)println (Thread.CurrentThread (). GetName)Thread.Sleep (2000)}}}Object Second_actor extends Actor {Def Act () {for (I println ("Step further:" + i)println (Thread.CurrentThread (). GetName)Thread.Sleep (2000)}}}Object Hello_actor {def main (args:array[string]): Unit = {First_actor.start ()Second_actor.start ()}}Report:This blog description:1. Organize

This course focuses onSpark, the hottest, most popular and promising technology in the big Data world today. In this course, from shallow to deep, based on a large number of case studies, in-depth analysis and explanation of Spark, and will contain completely from the enterprise real complex business needs to extract the actual case. The course will cover Scala programming, spark core

One of the core features of functional programming is to pass functions as parameters to functions, to define functions inside functions, and so on.1, hands-on Scala high-order functionsDeclares a list collection instance: The package that contains the list collection is already pre-defined and automatically imported, so there is no need to import the package here, and this is where the list instantiat

3, hands-on generics in Scalageneric generic classes and generic methods, that is, when we instantiate a class or invoke a method, you can specify its type, because Scala generics and Java generics are consistent and are not mentioned here. 4, hands on. Implicit conversions, implicit parameters, implicit classes in Scalaimplicit conversion is one of the key points that many people learn about Scala, which i

3, hands on the abstract class in ScalaThe definition of an abstract class requires the use of the abstract keyword: The above code defines and implements the abstract method, it is important to note that we put the direct running code in the trait subclass of the app, about the inside of the app helps us implement the Main method and manages the code written by the engineer;Here's a look at the use of uninitialized variables in an abstract class: 4, hands-on trait in ScalaTrait

Some time ago Read the "Fast Learning Scala", feel that writing is not very good, so began to see this "programming Scala", the book's Code has been realized a bit, now put in the blog to share. Package BASE04 /** * Scala's class * Created by DD on 2016/5/18 0018. * /Object demo01 extends app{ class car (val year:int) { private var milesdriven:int =

+ ")" ) }} The Talkpoint class above inherits from point, noting that its default constructor, X, Y does not have a Val decoration before, and extends point (x, y) will automatically call the base class's constructor. We can call this subclass's Talk method by using the following codeObject app { def Main (args : Array[string]) { val P = new talkpoint (0,0 p. () }} Run the program output: My position is (0,0)Methods for overriding base classesNext we create a subclass of Talkpoin

This article is mainly about Scala concurrent (parallel) programming, then why the topic is called Geotrellis use (vi), mainly because this series explains how to use Geotrellis, the specific previous several blog has been introduced. I think the basis of doing any one thing is very important, like the college entrance examination or a variety of examinations, teachers will emphasize the basis, which is ver

Previous Article: Scala Tutorial: interaction with Java, everything is an object This document is translated from the official Scala tutorial. to prevent misunderstanding, keep the original document for reference. Due to space limitations, there are three articles. Blog formats are not easy to adjust, interested friend

)), (1+ (0+1)) + (0+1) + (1+ (0+1))) = Go (1,3,5)7 Go (0,5,8) = 5Is the answer we expected.The function of Scala is worth mentioning. A function can be used as a standard object: it can be treated as an input parameter or a result value of another function. Functions that accept a function as an input parameter or return another function as a result are called higher order functions (high order function). The use of anonymous functions (anonymou

, but it also has a wide range of "native" libraries to handle large-scale data (especially Twitter's algebird and Summingbird). It also includes an easy-to-use REPL for interactive development and analysis, just as with Python and R.I personally love Scala because it includes many practical programming features, such as pattern matching, and is considered much simpler than standard Java. However, using

(Bus). Only through horizontal expansion (scale out), that is, distribution expansion by increasing the computer server and then using the distributed computing technology to divide the computational task into discrete servers for processing; This is the core of big data technology.Predictably, we will face the future: distributed data, high concurrency processing, parallel computing, NoSQL and very large interactive complex network platform programming