scala in depth

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

To this chapter, the examples of all function texts refer only to the arguments passed in. For example, (x:int) => x > 0, the only variable used by the function body, x > 0, is x, which is defined as a function argument. However, you can also refer to variables defined elsewhere: (x:int) => x + much/more. 51CTO Editorial Recommendations: A special topic in Scala programming languages function to add "more" to the reference, but what is more it. From

=${java_home}/bin:$PATH 5 Execute java-version and javac-version if it can appear the instructions shown in Java installation complete　　Step Two: Install the Scala https://scala-lang.org/download/page to download1, wget https://downloads.lightbend.com/scala/2.12.6/scala-2.12.6.tgz2, unzip TAR-ZXF

Label: Introduced Scala is a kind of functional object-oriented language . It blends a lot of unprecedented features. At the same time, it executes on top of the JVM . With the growing interest of developers in Scala , and the increasing number of tools to support it, the Scala language will undoubtedly be an indispensable tool in your hands. MongoDB is a product

Original from http://blog.csdn.net/xiaoquanhuang/article/details/66137051) Intuitive understandingDepth is actually the distance of the pixel in the 3d world, and the depth cache stores the depth value of each pixel point (drawn on the screen)! The depth test determines whether to draw a farther pixel point (or a closer pixel point), which is usually relatively c

ObjectiveFirst of all, we want to emphasize one important thing at the outset: Scala's pattern matching occurs but is not limited to the match case statement block, which is one of the key factors that Scala pattern matching is important and useful! We will discuss this in detail in the latter part of the article.Types of pattern matchingThere are several types of pattern matching in Scala: Wildcar

Knowledge Points: 1. Simple class and no parameter method class Counter { private// must initialize field // method default is public def Current () = value}In Scala, a class does not declare that a Public,scala source file can contain multiple classes, all of which have common visibility. New // or New Counter () mycounter.increment () println (Mycounter.current ())Call the no parameter method, you c

1. Pattern matching is much more powerful than switch case in Java, in addition to matching values, types, collections, and so on, the most common case class matches, and Master.scala has a large number of pattern matches.Case "_" means an experience that does not satisfy all of the above scenarios, for example:def bigdata (data:string) {Data match{Case "Spack" =>PRINTLN ("WOW!!!")Case "Hadoop" =>println ("OK")Case _=>println ("sorry")}}Bigdata ("spack")//WOW!!!You can add conditional judgment t

1. Install JDK 2. Install Scala Download the scala program at http://scala-lang.org/ Wget http://scala-lang.org/files/archive/scala-2.10.4.tgz Tar-zxvf scala-2.10.4.tgz-C/OPT Ln-S/opt/sca