When creating a collection or a list do you always need to specify the type of whatever is in those structures with lt gt like Collection lt Int gt Can t you make a list that has both Int and Strings

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

04/21/2017, 1:12 PM

You can store both Int and String in

Collection<Any>

kirillrakhman

04/21/2017, 1:13 PM

type inference will automatically take care of that if you write

listOf(1, "foo")

vitruvia

04/21/2017, 1:13 PM

Ah, cool. Thanks!

kirillrakhman

04/21/2017, 1:13 PM

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

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

vitruvia

04/21/2017, 1:14 PM

so operations on it will be dynamically typed?

kirillrakhman

04/21/2017, 1:15 PM

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

04/21/2017, 1:16 PM

I think i get it

kirillrakhman

04/21/2017, 1:17 PM

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

vitruvia

04/21/2017, 1:19 PM

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

04/21/2017, 1:20 PM

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

04/21/2017, 1:20 PM

Thanks, I'll read about it, then.

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