scala akka

Scala basic Concept +ideRecommended: "Scala Programming"1 Basic ConceptsIn spark development, Scala is considered to be the best-compatible language for current and spark. Scala run on a standard Java platform that can be used with Java seamless interaction.

I. Basics 1. VariablesVal identifier: Declares constants. For example, Val answer = 1.VaR flag: declares a variable; Type inference: Scala deduce the type of a variable based on the expression of the initialization variable; Val is encouraged; Note: An error is reported if the variable is declared without initialization. Explicit type: Scala variables or functions are always written after variables or

Because Scala has a more complete Eclipse IDE (Scala IDE for Eclipse), it's easy, fast, and convenient for Dev who doesn't want to migrate from Eclipse to the IEA platform. It is particularly important to compile and package the development of Scala applications under Eclipse. SBT is a build tool similar to MAVEN, which we will use to build the publishing program

Use of 1.Scala ReplInstall Scala and append the bin directory of the Scala installation directory to the PATH environment variable. In this case, you can enter Scala directly under CMD to enter REPLEnter REPL, and you can enter a valid expression in Scala after the command p

Scala Featured Tutorials-case class and pattern matching Scala Featured Tutorials-case class and pattern matching (1): A simple Demo sample Scala Featured Tutorials-case class and pattern matching (2): type of pattern (i) Scala Featured Tutorials-case class and pattern matching (3): type of pattern (ii)

methods for traversing collections 1. Iterating through a collection with a foreach Loop foreach receives a function as a parameter. The defined function should receive an element as an input parameter, and then do not return anything. The type of the input parameter should match the type in the collection. With the execution of foreach, it passes an element to your function every time, until the last element in the collection. The most common use of foreach is output information:

The concepts of classes and methods in Scala are similar, and here are just some of the important concepts of Scala: 1.Public is the default access level for Scala and can be omitted. An important feature of the method parameters in 2.Scala is that they are all Val, not Var (the argument is Val is easier to articulate,

To create a string: The most straightforward way to create a string is to write a method that: var greeting = "Hello world!"; Or var greeting:string = "Hello world!"; Whenever you encounter a string in code, the compiler creates a string object and its value in this example using: "Hello world!", but if you like, you can give the string, because here I have alternately shown in the declaration. Object Test { Val greeting:string = "Hello, world!" def main (args:array[string]) { printl

First lesson: Getting Started with ScalaThe great value of 1:scala2:scala basic function Getting started combat3:scala function Getting Started combatArray,map,tuple Combat in 4:scala5: Comprehensive case and spark source code analysisThe relationship between Scala and Java:One: They're all JVM-based, but Scala can inv

Knowledge Points: 1. Conditional expression if (x>0) 1 Else 0 Scala each expression has a type, if it is the same type, and if it is a mixed-type expression, the public superclass of any.if (x>0) 1 may not have output values, in Scala, each expression should have some value, introducing the Unit class, writing (). if (x>0) 1 is equivalent to if (x>0) 1 else () 2. Statement termination, if you write a long s

A systematic study of Scala has recently begun. In fact, I used Scala before, for example, when I was using Gatling's performance testing tool, I was exposed to Scala. Gatling itself is written in Scala, and the Gatling performance Test profile itself is a Scala class that i

The main contents of this section Introduction to Scala I/O operations Scala Writing Files Scala Read files Scala Network I/O Introduction to Regular expressions Scala regular-expression combat 1. Introduction to

ArrayLike an array of Java, it is also an immutable arrays, and since both Scala and Java are running in the JVM, both sides can call each other, so the bottom of the Scala array is actually a Java array. Note: Accessing an array of elements using () instead of [] in Java Scala>ValA =NewArray[string] (Ten) a:array[string] = Array (NULL,NULL,NULL,NUL

The first step is to build the Scala development environment and find tutorials on the web.declaring constants and variablesval foo = 0 //constant var bar = 0 //variable　　In Scala, it is more encouraged to declare using Val, which is the recommended constant. Most of the time do not need a semicolon, look at their own good ... Although it is a strongly static type of language, it does not write the type-t

1, Scala and Java have 7 numeric types: int, short, long, byte, float, double, Boolean 7 kinds, but in Scala, these 7 types of values are classes, in Java, the basic type, Java, Data types are divided into basic types and reference types, which are not differentiated in Scala.2. The type of a variable or function in Scala