What's wrong with ```if (list is ObservableList&lt...

# announcements

[Juan]

What's wrong with

if (list is ObservableList<Course>)

? it's displaying this error "Cannot check for instace of erased type: ObservableList<Course>"

[Czar]

the <Course> part does not exist at runtime, due to JVM's generic type erasure, so the is check is not possible.

[Juan]

Is there a workaround or something? @Czar

[cygnus]

this isn't very pretty nor do i like it much but you can call some non-mutator method that returns an object inside of that list and check the type of that

[cygnus]

so for instance, if(list.get(index=0) is Course)

[Czar]

Note if you check first element, you're out of luck if your list can be empty
You could also use a wrapper (also not very pretty)

class ObservableListOfCourse(val value: ObservableList<Course>)

if (listWrapper is ObservableListOfCourse)

[cygnus]

it's an observable list, of course XD

[cygnus]

^ a bad pun sorry

[Czar]

But more often then not you can refactor it so that you don't need an is check.

[cygnus]

yep

[Czar]

And you may find this useful: http://rgomes-info.blogspot.com/2013/12/using-typetokens-to-retrieve-generic.html

[Caleb Allen]

If you only need to check the list type, I believe you can use is ObservableList<*>

[Juan]

@Caleb Allen I need to check list items type also