udemy scala

Recently re-built a Maven+scala environment, found a lot of things do not remember, and then re-record again.If you have trouble building a problem, you can also download the official Scala environment http://scala-ide.org/download/sdk.html contains a lot of commonly used plugins, but does not use Maven but SBT, But in the domestic for some reason SBT speed is ve

immutability and functional programming to make my efficiency a big boost. Based on the dynamic nature of Lisp, I can always shape clojure into a state that fits the best abstraction. There would be no difference if there were no clojure,storm, but the process would be much more painful. "The next generation of distributed computing systems spark not only chooses Scala in its implementation, it also provides the preferred programming language for

PS: haven't written blog for a long time, 1 is not to write, 2 is not what dry. Recently accumulated some things, can be taken out of the sun. Ha ha. First of all, boss let me simplify the code of case class copy to make it easy to read. Case Class A (a:string,b:int) Cases Class B (a:a,b:int,c:string) Val B = B (A ("a", 2), 3, "C") B.copy (A.copy (b=2))//above is a simple example,If the case class is multiple nested, it produces a similar//a.copy (B.copy (c.copy (D.copy ...). Extra-long code. At

Scala Programming implicit conversion and implicit parameter introduction Scala offers an implicit conversion and implicit parameter functionality that is very feature-specific. is a feature that is not in programming languages such as Java. It allows you to manually specify that an object of some type be converted to another type of object. With these features, you can achieve very powerful, and special f

When I was learning Scala today, I suddenly wanted to use idea to create a learning class (the CMD code was too painful) to create a class directly: Class Test { def main (args:array[string]) { print ("Hello world!") } } When I want to run this main function, the lack of execution, then depressed, again look at the new, just know, Scala class classification: What's the difference between the t

Learn how Java next-generation languages reduce boilerplate code and reduce complexity The limitations faced by the Java programming language at birth are different from those faced by today's developers. Specifically, there are primitive types in the Java language due to the performance and memory limitations of hardware in the middle of the 90 's. Since then, the Java language has evolved, with automatic boxing (Autobox) eliminates a lot of hassle, and the next language (Groovy,

Https://github.com/derekwyatt/vim-scala provides a choiceLook at the install manual and find that two commands are required.mkdir -P ~/.vim/{ftdetect,indent,syntax} for in ftdetect indent syntax Do wget --no-check-certificate-o ~/.vim/$d/scala.vim https:// raw.githubusercontent.com/derekwyatt/vim-scala/master/$d/scala.vim; DoneThen install Vim-scala via Vu

Overloaded Methods and fields The unified access principle is just one aspect of Scala's more unified approach to fields and methods than Java. Another difference is Scala, where fields and methods belong to the same namespace. This makes it possible to overload the field with a parameterless method. For example, you can change the implementation of a contents in a class arrayelement from one method to a field without having to modify the contents ab

1. Array2, ArrayBuffer3. Traversing array and Arraybuffer4. Common Array Operations1. ArrayIn Scala, array stands for a similar meaning to Java and is an immutable array of lengths. Since both Scala and Java are running in the JVM, the two sides can call each other, and the underlying implementation of the Scala array is actually a Java array.　　2, ArrayBufferIn

1. Development environment 1.1. Package Download 1.1.1. JDKHttp://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.htmlInstall to the D:\GreenSoftware\Java\Java8X64\jdk1.8.0_91 directory 1.1.2. Mavenhttps://maven.apache.org/download.cgiUnzip to the D:\GreenSoftware\apache-maven-3.3.9 directory 1.1.3. Scalahttps://www.scala-lang.org/download/Unzip to the D:\GreenSoftware\Java\scala-2.12.6 directory 1.1.4. ThriftHttp://thrift.apac

To look at Scala from an object-oriented perspective, Scala can be said to be a purely object-oriented programming language, because everything in Scala can be viewed as an object. This is different from Java, which distinguishes between basic data types and reference types. Numeric objects 5210000 + 1 *1024/1 This is the basic operation in Java, but

why not suggest return in Scala Using return in Scala, the compile will prompt the latest statement is method is automatically returned, and use of th return keyword is redundant. The warning is that the result of the last statement is automatically returned, and no return statement is required.Scala does not recommend using the return keyword, which is very uncomfortable when you are just touching functio

I. BACKGROUNDBecause of the project needs, the MySQL database needs to be connected to the Sbt+scala project. As a result of the previous use of Maven+java to rely on management, in the Sbt+scala aspect is also constantly groping, hereby recorded, as a small module accumulation of knowledge.Second, the system environmentThe versions of Scala, SBT, and IDE are as

Scala and SBT are installed by default and have a basic understanding of SBT and know how to build a project with SBT.Add dependencyTo use the PostgreSQL database in Scala, you need to import PostgreSQL driver-related library files, PostgreSQL library files, can be downloaded to their official website, be sure to download and your Scala, JDK corresponding version

Win7 installing Scala 2.111. Download Scala 2.11http://download.csdn.net/download/u014393736/7107595I really download the Scala installation files, in fact, is a compressed package, just need to extract the files can be!You can also download the MSI suffix file on the website to install it.The installation process is as follows:The advantage of downloading the MS

The main contents of this section Trait Construction Order Comparison of trait and classes Pre-defined and lazy loading Trait extension Classes Self type 1 Trait Construction OrderIn the previous note, we mentioned that for trait that do not have a specific implementation and a field, it will eventually generate a bytecode file that is equivalent to the interface in Java, whereas for trait with specific implementations and fields, the bytecode file is compiled with

Mappings and tuples Summary :A classic programmer's famous saying is: "If there is only one data structure, then use a hash table." A hash table , or more generally, a mapping , is one of the most flexible data structures. A map is a collection of key/value duality . Scala has a common term: tuples, which are aggregates of N objects, do not necessarily have the same type . duality is simply a n=2 tuple, and tuples are especially useful for

Tag: Spark installs Scala1. Download SparkHttp://mirrors.cnnic.cn/apache/spark/spark-1.3.0/spark-1.3.0-bin-hadoop2.3.tgz2. Download ScalaHttp://www.scala-lang.org/download/2.10.5.html3. Install ScalaMkdir/usr/lib/scalaTAR–ZXVF scala-2.10.5.tgzMV Scala-2.10.5/usr/lib/scala4. Set Scala pathVim/etc/bashrcExport scala_home=/usr/lib/

Scala supports associative mappings, such as a key-value pair that can be represented by (key, value) All types in Scala are objects, including basic data types The case statement in Scala is used to determine the received message, which is more than the switch...case in Java ... More focusedreceive{Case msg = action ()} The

In the previous chapter we introduced and then used the interpreter to write simple Scala code, and here's how to write a Hello word! using eclipse Open Eclipse. Create a new Scala Project. The first new words should be in other, name casually, then create a new Scala Object named "HelloWorld". Unlike Scala and Java, t