udemy scala

public number is Dt_spark, every day will have big data actual combat video release, please continue to study.Liaoliang DT Big Data dream factory Scala all videos, PPT and code in Baidu Cloud disk link:http://pan.baidu.com/share/home?uk=4013289088#category/type=0 Qq-pf-to=pcqq.groupLiaoliang "Scala Beginner's introductory classic video course" http://edu.51cto.com/lesson/id-66538.htmlLiaoliang "

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

Package Com.leegh.parameterization/*** @author Guohui Li*/Class PersonClass Student extends PersonClass C[+t] (Val args:t)Trait Friend[-t] {def makefriend (Somebody:t)}Object Variance {def makefriendwithyou (S:student, f:friend[student]) {f.makefriend (s)}def main (args:array[string]): Unit = {Val Value:c[person] = new C[student] (new Student)}}Report:This blog description:1. Organize your ideas and improve yourself.2. Be educated in Liaoliang teacher, what to gain, so recommend.3. Blog focus on

In the first two sections, we learned about Scala's objects and associated objects, both of which are used to mean the static members of Java. There are no static fields and static methods in Scala. A static member destroys the complete object-oriented model that Scala supports. However, it is possible to implement class-level operations on Scala through the asso

Package Com.leegh.parameterization/*** @author Guohui Li*/Class Pair[t def bigger = if (First.compareto (second) > 0) First Else second}Class Pair_lower_bound[t] (Val first:t, Val second:t) {def Replacefirst[r;: T] (newfirst:r) = new Pair_lower_bound[r] (Newfirst, second)}Object Type_variables_bounds {def main (args:array[string]): Unit = {Val pair = new pair ("Spark", "Hadoop")println (Pair.bigger)}}Report:This blog description:1. Organize your ideas and improve yourself.2. Be educated in Liaol

First, prefaceThe Scala program uses Unicode's BMP character set (Wiki:bmp character set), which is not currently supported by the Unicode supplement character set. This chapter defines Scala's syntactic analysis from Scala models and XML models. If not specifically mentioned, the default refers to the Scala model and specifies that the characters are ASCII \u000

Scala code in one day (7) and scala code in one dayScala code in one day (7)To better control spark, I recently studied scala language features, mainly reading "quick learning scala" and writing down some codes that I think are useful. Package examplesclass Angela {// package visibility This specifies that this method

Scala code in one day (9) and scala code in one dayScala code in one day (9)To better control spark, I recently studied scala language features, mainly reading "quick learning scala" and writing down some codes that I think are useful. Package examplesimport scala. io. sour

Package Com.leegh.parameterization/*** @author Guohui Li*/Object Type_contraints {def main (args:array[string]): Unit = {def Rocky[t] (i:t) (implicit ev:t println ("Life is too short,you need spark!")}Rocky ("Spark")}}Report:This blog description:1. Organize your ideas and improve yourself.2. Be educated in Liaoliang teacher, what to gain, so recommend.3. Blog focus on practice, superfluous words are not much to say, are doing technology.4. Information from DT Big Data Dream Factory public accou

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/6F/91/wKioL1WhEYHR0V55AAi8dfKDnAg782.jpg "title=" 002- Scala function definition, Process Control, exception handling get started in combat. png "alt=" wkiol1wheyhr0v55aai8dfkdnag782.jpg "/>002-scala function definition, Process Control, exception handling getting started combatScalafunction Definitionstatement end no semicolondefining an parameter

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

Scala code in one day (5) and scala code in one dayScala code in one day (5)To better control spark, I recently studied scala language features, mainly reading "quick learning scala" and writing down some codes that I think are useful. Package examplesclass Person {val publicVal = 1 // automatically generate getter var

Answer the previous article.1. Is there also a syntax for declaring upper bound and Lower Boud in Java? Some, such as:ListWhat is the difference between listListListPackage Tstge;import java.util.*;p ublic class Tst {public static void main (string[] args) {arraylistThe type of 3.Java can usually be translated directly into the Scala type. But like IteratorIterator[t] Forsome {type T} or Iterator[_]Iterator[t] Forsome {type T About Forsome,stack overf

1, Java Operation Test jar: Execute---java-classpath f:/testhello.jar Test2 Or JAVA-CP F:/testhello.jar Test2 Print Results: Hello World The Java classes are as follows: /** * Document: This kind of function----> Print Hello World * USER:YANGJF * date:2016/9/25 9:48 /Public Class Test2 {public static void Main (string[] args) { System.out.println (' Hello World '); } 2, Scala operation Test jar: Execute--"

High-order function filter Source analysisPackage Com.dt.scala.forexpressionCase class Person (name:string, Ismale:boolean, children:person*)Object For_expressive {def main (args:array[string]) {Val Lauren = person ("Lauren", false)Val Rocky = person ("Rocky", True)Val Vivian = person ("Vivian", False, Lauren, Rocky)Val persons = List (Lauren, Rocky, Vivian)Val result = Persons filter (person =!person.ismale) FlatMap (person =(Person.children map (child = (Person.name, child.name)))println (Resu

The Akka provides scalable, real-time transaction processing capabilities.The Akka is based on actor and provides location transparency.The 1GB heap can have 2.5 million actors.Horizontal expansion, vertical expansion, fault tolerance 3 ways to solve.The actor of the tree structure, each actor has state and behavior.DT Big Data Dream Factory public account: Dt_spark.DT Big Data Dream Factory's public number is Dt_spark, every day will have big data actual combat video release, please continue to

= { //similar to defining a static method initialization, using C to refer to a method var c=c () c.apply () c.test () }}3. Use apply to achieve a singleton mode, let's do a test. Reference the associated object C with C and C1, respectivelyPackage Smart.iotclass Applyclass { }class a{ def Test () =println ("function test") def apply () =println ( "Hello class A");} Object b{ def apply () =println ("Hello object B");} Similar to a factory method, use the C apply method

Note: This study originates from: DT Big Data DreamWorks (public number: Dt_spark)In Scala , we usually use syntax similar to function calls. For example, if s is a string, then s (i) is the first character of the string . (And in java , you would write:s.charat (i).) Run the following code in idea:println ("Hello (4)")//will print out ' o 'You can use this as an overloaded form of the () operator, and the implementation behind it is a method called

001-scala Development environment Construction and HelloWorld parsing650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/6F/7A/wKiom1Wd1vGx30HBAAST-S83WFU734.jpg "title=" 001- Scala development Environment Building and HelloWorld parsing. png "alt=" wkiom1wd1vgx30hbaast-s83wfu734.jpg "/>scalafunctional programming and object-oriented languagefunctional Programming excels at numerical calculationsObj

Upper bound and lower bound Declare Lower bound with:>, which is the parent class constraint, a:> B, a must be the parent of BWith Examples of Lower boundPackage Ch6object Test4 {println ("Welcome to the Scala Worksheet") class A {type B;: List[int] def foo (A: B) = a} val x = new A {type b = Traversable[int]} Set (1) X.foo (set (1))//Val y = new A {type b = set[int ]}//Compilation Error}Thus, the meaning of a:> B is: The parent class of B or a t