What does first parameter `<X>` stand for? I...
# announcementsd
Davor Maric
05/15/2018, 12:24 PMWhat does first parameter
<X>a
Andreas Sinz
05/15/2018, 1:01 PMXd
Davor Maric
05/15/2018, 1:24 PMWhat I was looking for is generic functions.. but I don't get the point of it.. is this
Copy code
fun <T> singletonList(item: T): List<T> { // ... } Copy code
fun singletonList(item: T): List<T> { // ... }Davor Maric
05/15/2018, 1:25 PMwhat the removed param stands for? It isn't return type as return type is specified after (args):
a
araqnid
05/15/2018, 2:28 PMit specifies that the function call needs to have a T parameter inferred from the context it was called from
araqnid
05/15/2018, 2:29 PMIf you leave the <T> out in the lines above, then it will simply say it's unknown -- by putting it there you're "declaring" it local to the function declaration
araqnid
05/15/2018, 2:29 PM(as opposed to inheriting it from the class the function is a member of or whatever)
araqnid
05/15/2018, 2:30 PMspecifically in this case, you're specifiying a constraint: the same type you pass as an argument is to be used for the return type
d
Davor Maric
05/15/2018, 2:47 PMI am coming from Java World.. does this stuff exist in Java?
a
araqnid
05/15/2018, 3:29 PMyes, Collections.singletonList() has a type parameter there too