In Kotlin you can do something like this:
val s: String = "Hey"
println(s[1])
or simply:
println("Hey"[1])
and you will print e
.
But what if you want to extend this behavior to your own classes? What interface do you need to implement to accomplish this syntax?
I looked at String
's supertypes and only found Comparable<String>
and CharSequence
, neither of which had any other supertypes themselves, so my quest ended early.
For example in Python, by defining a method called __getitem__
in a class, you can bestow the objects of that class the ability to be used with square brackets syntax like this a[i]
; I was wondering how this was possible in Kotlin.
Thanks in advance.
CodePudding user response:
You can use Kotlin's operator overloading, specifically the overloading for indexed access operators.
The syntax "Hey"[1]
is just an alias for "Hey".get(1)
(if not on the left-hand side of an assignment, where it would be an alias for "Hey".set(1, ...)
).
CodePudding user response:
Apparently just having a method get(i: Int)
suffices. Interesting...