Student - MapOf question

Language Design
1

Hi there,

Could someone point me to or explain how I would access a specific key in a multilayered map.

Here is a sample:

val letters = mapOf(
“A” to
Letter(
name = “A”,
description = “Apple”
),
“B” to
Letter(
name = “B”,
description = “Banana”
))

If I wanted to access the description of B. How would that look?

Val bdesc = letters[“B”].Letter.description?

2

It depends on your approach, but for example you can use one of those options:

val bdesc = letters["B"]?.description // null-safe way

val bdesc = letters["B"]!!.description // forceful way

val bdesc = letters.getValue("B").description // forceful way 2
1 Like
3

I won’t have to reference to Letter? The instance holding the information for “B”. Where letters is the map.

4

No, .Letter doesn’t make sense here. There is no object with Letter property. Similarly, you don’t access the map of letters with letters.Map, but just letters.

1 Like
5

The map maps strings to objects of type Letter. So letters["B"] returns a Letter, and you can access the Letter’s fields directly.

1 Like