scala zero

From Scala wizard Chapter 1 functional objects With the basic Scala knowledge gained from the previous chapters, you are ready to explore how to design objects with more comprehensive features in Scala. This chapter focuses on defining functional objects, that is, classes of objects without any variable states. As an example of running, we will create several Cl

, so the throw expression can be used where the type is needed.Def divide (X:int, y:int): Int = { ifthrownew Exception ("Divide by Zero") c6/>Else x/ y}The return type of the above code divide method is int, because throw new Exception("Divide by zero") the type is nothing and is a subclass of int, so the above code is correct.5.2. Catching exceptionsThe mechanism of exception snapping is the same as in ot

as:Def divide (X:int, y:int): Int = { if (y = = 0) error ("Divide by Zero" )else x / y}The Divide method above requires an int value to be returned, but nothing is acceptable if there is an error.Another use is where there is generics, because Scala supports covariance (it doesn't matter if you don't understand covariance), nothing can replace other types when necessary. For example List[Nothing] , it ca

example:def error(msg:String):Nothing={ throw new RuntimeException(msg) }def divide(x: Int, y: Int): Int =if0) x / yelse error("can‘t divide by zero")4 Traits IntroductionScala, like the Java language, employs a strong restriction strategy that avoids multiple inheritance problems. In the Java language, only one superclass is allowed, and the class can implement multiple interfaces, but the Java interface has its own limitations: The interface ca

First, Scala overviewcan expand? Object Oriented? function-type programming compatible with Java Interop Syntax concise ? code line short ? ? abstract control statically typed can examine secure refactoring support concurrency control Customize other control structures Ii. installation of ScalaIdeEclipse (native support, use more complex)IntelliJ (expensive)NetBeans

For details about the/dev/null and/dev/zero files, and solutions for accidental deletion of/dev/null and/dev/zero, and the disk I/O Testing Method Using/dev/zero, disk deletion and recovery by mistake1. Introduction-explanation from Wikipedia/dev/null: In Unix-like systems,/dev/null, or an empty device, is a special device file that discards all data written into

1, Introduction--From the wiki interpretation/dev/null:In a Unix-like system, a/dev/null, or empty device, is a special device file that discards everything written to it (but reports a successful write operation) and reads it immediately to get an EOF.In programmer jargon, especially in Unix jargon,/dev/null is called a bit bucket or black hole. Empty devices are often used to discard unwanted output streams, or as empty files for input streams. These operations are usually done by redirection.

Tags: nbsp idea Big Data development GTK Target 1.3 website startup technology sharingStep Two: Install IntelliJ idea　If 3 nodes such as Master, Slave1, Slave2, it is recommended to install it on the master nodeTo Https://www.jetbrains.com/idea download the corresponding version of the file,Because, I usually install the JDK myself, without the openjdk of CentOS, so I download the version as followsThen unzip it.The following is the directory where IntelliJ idea was installedThen proceed to the

Detailed description of/dev/null and/dev/zero files, solutions for accidental deletion of/dev/null and/dev/zero, and disk I/O testing using/dev/zero1. Introduction-explanation from Wikipedia/dev/null: In Unix-like systems,/dev/null, or an empty device, is a special device file that discards all data written into it (but reports a successful write operation ), read it to get an EOF immediately./Dev/

Scala tutorial, scala Programming The following is a complete scala getting started tutorial I have collected from the Internet. I have followed other programming basics to get started. Compared with other languages such as Java, Scala is a complex language. It is a unity of object-oriented and function-oriented. It is

Scala supports scripts 1) create a file hello. Scala under/opt/Scala-script and edit the file as follows: $ Hello, this is the first Scala script 2) run the script 　　　　 The command line parameters of the scala script are saved in the sc