Map Explained - Kotlin Collections

In this video we talk about the map function that is part of the Kotlin collections library. Using map allows you to transform a collection from one type to another.
As with every single video I do about software engineering, if you have any questions or comments please let me know below 😊
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[@dewetvanrooyen8458]

Great vid thanks.

[@gilong1311]

Great video, subbed! :)

[@CodyEngelCodes]

Thanks for the sub!

[@mattgraves3709]

Almost like table joins in SQL...but with Kotlin code lol.
Neat and 'modern' way to express things

[@BrianPondiGeoGeek]

Awesome

[@CodyEngelCodes]

Thanks ☺️

[@ivanstrelka3448]

Thanks

[@CodyEngelCodes]

Yeah, you're welcome ☺️

[@jeffluo9591]

Very cool and efficient code, but I think I will stick with good old For Next loop for now just to avoid confusion.

[@CodyEngelCodes]

What sort of confusion are you trying to avoid?

[@pheroqt1238]

When we extract an object from another object and throw it into an array list, do you suggest to use double map function or one map + add to empty array list for that?

[@CodyEngelCodes]

The map function is available on collections and sequences. Using the map function to add it to a new list is not a great idea since it will break the chain. I’m not quite sure I’m following your use case, if it’s not working from a collection or sequence though I wouldn’t use map at all (it also likely isn’t available as an option).

[@pheroqt1238]

@@CodyEngelCodes I figured out several ways to do it. At last I decided on something like this. If you have a better idea, I would hear :
val arrayOfData2 = response.data1.children.map {
it.data2
}.toList()
listAdapter.updateList(arrayOfData2)

[@nanditaekambaram9609]

I’ve a silly doubt , the first map function added to books gives us a book object , which returns authors . Adding map to that should give us an author object instead of list of authors

[@CodyEngelCodes]

The collections operators return collections, if we did map followed by first it would give us a single author back. Alternatively if this was done on a sequence instead of a list then it would return one author at a time but you’d still collect that into a list at the end (most likely).

[@brunodiaz6100]

Hi, maybe the example is a little complex to understand for someone that doesn't know what map is.

[@grand_duke9225]

Yes, i concur.

[@grand_duke9225]

Hi Cody. I love this video but the example is too complex. Remember people watching are either newbie or have no idea on how to use map

[@somith16]

waste of time

[@CodyEngelCodes]

Oh?