Scala Main class

Adding a main class is Scala is something that I always end up searching so next time it shall be through my blog.

You can go for the extends App option

One way is to add a main class by extending the App class. Everything else that get’s executed on that block is part of the “main” function.

package com.gkatzioura

object MainClass extends App {

  println("Hello world"!)
}

Then you can access the arguments since they are a variable on the App.

package com.gkatzioura

object MainClass extends App {

  for( arg <- args ) {
    println(arg)
  }

}

Add a main method

This is the most Java familiar option

package com.gkatzioura

object MainClass {

  def main(args: Array[String]): Unit = {
    println("Hello, world!")
  }

}

As expected you receive the program arguments through the function arguments.

package com.gkatzioura

object MainClass {

  def main(args: Array[String]): Unit = {
    for( arg <- args ) {
      println(arg)
    }
  }

}