is there any difference in these two

val isEmpty: Boolean
    get() = this.size == 0

val isEmpty =  this.size==0

yes, in first case it will be getter method with

this.size == 0

body, in second you just initialize property

you beat me to it

Yep, when the size changes, the value returned from the second property won't get updated

In other words, the second one is an immutable property with a backing field that can't change while the first ont is a read only property that returns isEmpty according to the curreny value of size

In these cases - where you want to use the first one because you don't want the immutable property - is it better to use a function instead of a val/override get, or are they effectively the same?

@adam-mcneilly Computed read-only properties are fine and idiomatic, in fact you can see a lot of them in the stdlib, especially in collections