Scala Basics

Run a small program with an entry point.

Scala

object Main {
  def main(args: Array[String]): Unit = {
    val name = "Ada"
    println(s"Hello, $name")
  }
}

Output

Hello, Ada

Explanation

The main method is called when the program starts. val binds an immutable value, and println writes it.

Explore the dry run

Guided walkthroughReady

1object Main {

2 def main(args: Array[String]): Unit = {

3 val name = "Ada"

4 println(s"Hello, $name")

5 }

6}

Start to inspect the source, values, and output. These prepared steps explain the published sample; grouped loop steps describe multiple iterations.

View the complete dry-run table

Prepared trace of the published program. Some rows group repeated iterations.
Step / line	What happens	State after step	Output so far
	Create immutable name when main runs.	`name = "Ada"`	—
	Interpolate name into the string and print.	`name = "Ada"`	Hello, Ada