Scala Hello World
原创转载请注明出处:http://agilestyle.iteye.com/blog/2331800
HelloScala.scala
package org.fool.scala.helloworld object HelloScala { def max(x: Int, y: Int): Int = { if (x > y) x else y } def greet() = println("Hello World") /* Scala has two kinds of variables, vals and vars. A val is similar to a final variable in Java. Once initialized, a val can never be reassigned. A var, by contrast, is similar to a non-final variable in Java. A var can be reassigned throughout its lifetime. */ def testValAndVar() = { val msg = "Hello Val" println(msg) var msg2 = "Hello Var" println(msg2) msg2 = "Hello Var again" println(msg2) } def main(args: Array[String]): Unit = { // Hello World println("Hello World") // Hello World greet() /* Hello Val Hello Var Hello Var again */ testValAndVar() // Hello, Spark println("Hello, " + args(0)) // Spark Hadoop MapReduce HDFS var i = 0 while (i < args.length) { print(args(i) + " ") i += 1 } println() // Spark Hadoop MapReduce HDFS args.foreach(arg => print(arg + " ")) println() /* Spark Hadoop MapReduce HDFS */ args.foreach(println) // Spark Hadoop MapReduce HDFS for (arg <- args) print(arg + " ") println() // 3 println(max(2, 3)) // -2 println(max(-2, -3)) } }
Pogram arguments
Console Output