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

Creating a Map

Like lists and sets, maps are created using functions: mapOf and mutableMapOf. You will be using mapOf to create a map representing the amount of gold in various characters’ purses. For now, you will only track balances for Madrigal and Taernyl – you will come back to handle your randomly generated patrons later in this chapter.

Create your first map in Tavern.kt. (We will explain the argument syntax shortly.)

Listing 10.1  Creating a read-only map (Tavern.kt)

...
fun visitTavern() {
    ...
    val patrons: MutableSet<String> = mutableSetOf()
    val patronGold = mapOf(
        TAVERN_MASTER to 86.00,
        heroName to 4.50
    )
    while (patrons.size < 10) {
        patrons += "${firstNames.random()} ${lastNames.random()}"
    }

    println(patronGold) ...