Scala for Backend Engineering & Functional Programming · Lesson

Expressions over Statements

Everything is an expression.

Expressions vs Statements

A statement does something but returns nothing useful. An expression evaluates to a value.

In Scala, almost everything is an expression. This is a core idea that shapes how you write code.

In many languages if is a statement. In Scala, if/else returns a value, so you can assign it directly to a val.

No need for a separate variable assigned in each branch.

object Main {
  def main(args: Array[String]): Unit = {
    val temp = 30
    val label = if (temp > 25) "hot" else "mild"
    println(label)
  }
}