What is the best way to write a main in scala?

Question

Since I have started to learn this language I've noticed that there are several ways to write a main method in order to run your code. What is the most used and best one?

Possible duplicate of [Difference between using App trait and main method in scala](http://stackoverflow.com/questions/11667630/difference-between-using-app-trait-and-main-method-in-scala) — FaigB, Mar 09 '17 at 11:14

score 3 · Accepted Answer · edited Mar 09 '17 at 12:20

3

This

object SO extends App {
    //Your main method's code goes here, since we have extended App
}

or

object SO {
  // here goes the main
  def main(args: Array[String]): Unit = {}
}

Personally I prefer the second one, as it distinguishes the main method more clearly.

edited Mar 09 '17 at 12:20

Yuval Itzchakov

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answered Mar 09 '17 at 11:14

Tawkir

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score 0 · Answer 2 · answered Mar 09 '17 at 12:07

As per your question, in general to run code as executable are used :

With mixing App trait

object RunCode extends App {
   println("Execute here")
}

or concrete main method inside object

object RunCode {
    def main(args: Array[String]): Unit = {
        println("Execute here");
    }
}

The App trait is a convenient way of creating an executable Scala program. The difference to the main method alternative is that the App trait uses the delayed initialization feature.

What is the best way to write a main in scala?

2 Answers2