scala programming tutorial

When programs get larger, you need some-to divide-them into smaller,More manageable pieces. For dividing up control flow, Scala offers a approach familiar to all experienced programmers:divide the code into FUNCT Ions. In fact, Scala offers several ways to define functions that is notPresent in Java. Besides methods, which is functions that IS membersOf some object, there is also functions nested within fun

effect. It is common practice to place an action in a class that implements an interface, and then pass one instance of the class to another method.To enable this syntax, you need to provide an implicit conversion.8. Assembly function ProgrammingThe function of the List,set collection is mainly the operation of Val list=list ("Scala", "Spark", "Hadoop") List.map (_) List.map (println) mutable (variable), immutable (immutable ) Scala.collection.Map: I

Today we learned the implementation of chained invocation styles in Scala, and in spark programming we often see the following code:Sc.textfile ("hdfs://..."). FlatMap (_.split ("")). Map (_,1). Reducebykey (_ + _) ...This style of programming is called chained invocation, and its implementation is described in the following code:Class Animal {def Breathe:this.ty

About Scala Programming examplesAt the beginning of learning a programming language, always want to write some relatively large programs and projects, but because the foundation is not solid, often make haste. So, only one step at a time, through some classic small examples to practice and exercise, and eventually continue to deepen the skills of

implicit object, then import the function of this type, and then the man can also be used under the function of implicit object in the implicit conversion. Implicit parameters, which can be used to transmit the parameters for an implied number of variables.First write a function:def talk (name:string) (implicit content:string) = println (name + ":" + content), the 2nd is an implicit reference, and then the talk-side If there are no implicit parameters, the editor will report it! At this poi

Chapter1 and Chapter2 Method definition: Def methodname (param1: paramtype, param2: paramtype2, [maybe more]): returntype = { // Method body } In functional programming, the conventional saying is,The method returns a value.Otherwise, a method will produce side effects, andAvoid side effectsIt is an original intention of functional programming. Array access: The array in

We recommend the responsive programming course on Coursera, an advanced Scala language course. At the beginning of the course, we proposed an Application Scenario: constructing a JSON string. If you do not know the JSON string, you can simply Google it. To do this, we define the following classes abstract class JSON case class JSeq(elems: List[JSON]) extends JSON case class JObj(bindings: Map[String, JSON]

to elements in a tuple.The type parameter in the TUPLE4 definition is preceded by a + sign, which represents the Covarience parameter and will be explained in depth later2. Set has two types, immutable and mutable, with the same name, creating immutable set objects by default650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/55/46/wKiom1SJYMeBdQOaAAF8Nvro-Is758.jpg "title=" 2014-12-11 17_15_07-programming in

Scala Programming Problem Sets (01)by GaoDongting International Intelligent Hardware testing baseQ-01: How to use Scala 's Singleton mechanism to express class-level data. Answer: NBSP; in object-oriented programming (oop,object-orientedprogramming) concept, attributes ( Attribute) and functions (function) are di

Today, I learned the 73rd lecture of Scala programming by Liaoliang, mainly the use of file selectors. Let's go through the code to try it out for yourself.Import Scala.swing._Import Java.io.FileImport scala.swing.event.ButtonClickedImport Scala.swing.LabelObject Gui_event extends simpleswingapplication{Val filechooser = new Filechooser (New File (".")) Define file selector, path to local filefilechooser.ti

Scala programming. Here is an example of writing to a file: Import Java.io._ Object Test { def main (args:array[string]) { Val writer = new PrintWriter (New File ("Test.txt")) Writer.write ("Hello Scala") Writer.close () } } When the above code is compiled and executed, it creates a file with "Hello Scala"

Here is a typical decision to make if ... Else the general form of the structure is used in most programming languages: If statement: The If statement consists of a Boolean expression followed by one or more statements. Grammar: Syntax for an IF statement: if (boolean_expression) { Statements'll execute if the Boolean expression is true } If the value of the Boolean expression is true, then the code module inside the IF statement is executed. If t

1.There ' s a fundamental difference between your own code and libraries ofOther people:you can change or extend your own code as you wish, but ifYou want to use someone else's libraries, you usually has to take them asThey is.You can change or expand your own code, but the code for others can only be accepted as it is.2.A number of constructs has sprung up and programming languages toAlleviate this problem. Ruby has modules, and Smalltalk lets packag

Concurrent programming in Java is mainly implemented by thread, and concurrency is realized through the mechanism of sharing resources, but it faces deadlock problem. In Scala, concurrency is achieved through message delivery, and actor is the implementation of message delivery. 1, actor first knowledge Package com.yy.enhance Import scala.actors.Actor /** * Scala