Kotlin Programming: The Big Nerd Ranch Guide, 2nd Edition

Named Function Arguments

Suppose the local village has a blacksmith. You might have a function with the following signature, which could be called to forge some new gear for Madrigal:

      fun forgeItem(
          itemName: String,
          material: String,
          encrustWithJewels: Boolean = false,
          quantity: Int = 1
      ): String = ...

One way to call this function is by passing arguments for all four parameters:

    forgeItem("sword", "iron", false, 5)

Another way to make the same function call is like this:

    forgeItem(
        itemName = "sword",
        material = "iron",
        encrustWithJewels = false,
        quantity = 5
    )

This optional syntax uses named function arguments and is an alternative way to provide arguments to a function. In certain cases, it grants several advantages. ...