When creating a collection or a list do you always...

# announcements

[vitruvia]

When creating a collection or a list do you always need to specify the type of whatever is in those structures with <>? (like Collection<Int>). Can't you make a list that has both Int and Strings?

[elizarov]

You can store both Int and String in Collection<Any>

[kirillrakhman]

type inference will automatically take care of that if you write listOf(1, "foo")

[vitruvia]

Ah, cool. Thanks!

[kirillrakhman]

of course that's not really in the sense of statically typed languages

[kirillrakhman]

whenever you access that collection you will need to do a type check before you can do anything with the item

[vitruvia]

so operations on it will be dynamically typed?

[kirillrakhman]

no

[kirillrakhman]

listOf(1, "foo")[0] returns Any. You can't do any Int operations on Any so you will have to do a is Int check.

[vitruvia]

I think i get it

[kirillrakhman]

this really isn't Kotlin specific, it's how statically typed languages work

[vitruvia]

Yeah its just that I only know python and there you don't have to do this type of check. So its all kind of new to me

[kirillrakhman]

in this case you might want to read up on statically typed languages. I doubt that it will take you long to grasp it.

[vitruvia]

Thanks, I'll read about it, then.