DT big data DreamWorks-Scala Learning Notes (1): Scala Development Environment Construction and HelloWorld Analysis
First, scala is a combination of functional programming and object-oriented programming. What are the characteristics of these two kinds of programming?
A: functional programming is good at numerical calculation; object-oriented programming is especially suitable for the organization of large projects or projects, as well as the division of labor and cooperation among teams.
Second, the characteristics of Scala
Scala is elegant in structure, exquisite in calculation and expressive.
What resources are needed for the installation of scala?
Java, it is recommended to install Java8 (Java7 is also possible)
Support scala 2.10.* or above (2.10.4, http://scala-lang.org/download can be installed)
4. Set environment variable (system variable):
(1) JAVA_HOME and SCALA_HOME
Determine the installation directory where JAVA and SCALA have been added (variables are C:\ Program Files\ Java\ jdk1.7.0_71 and C:\ Program Files (x86)\ scala, respectively)
(2) PATH
Make sure that% JAVA_HOME%\ bin and% SCALA_HOME%\ bin in the installation directory have been set in the variable value.
After adding SCALA's bin directory to PATH, use the SCALA command in any directory
(3) CLASSPATH
Add% JAVA_HOME%\ lib\ dt.jar;%JAVA_HOME%\ lib\ tools.jar to the variable value
5. View the version of the command:
Java-version
Scala
Use IDE integrated development environment to operate
1. IDEA, the first is IDEA. When developing Spark big data, IDEA is used to develop.
Because it supports JAVA and SCALA very well, and other supports are very good.
2. ScalaIDE (for eclipse), download, decompress and use it.
Beginners are strongly recommended to use ScalaIDE (for eclipse)
7. Establish the first procedure:
1. Create a project
Named: ScalaInAction
2. Create a package in the source code (easy to manage)
Set up packet under src
Named: com.dt.scala.hello
3. Create an object (after creating a package, you can write a program in it)
Named: HelloScala
Check "public static void main (String [] args)"
(Scala Object is a static object in the Scala class, and we have the main method entry of Scala in Scala Object)
Run As
The information comes from: DT big data DreamWorks Wechat Public account: DT_Spark
