Can someone review my code? Just started learning ...

# codereview

[alchzh]

Can someone review my code? Just started learning Kotlin this morning, so decided to port over some existing code... https://github.com/acz13/anagrams/tree/kotlin-rough/kotlin (x-post from #getting-started )

[dalexander]

I would rename the files so that they are capitalized, especially where they contains a single class (ie. bag.kt -> Bag.kt) In Bag#equals return num == (other as Bag).num; will cause a ClassCastException if other is ever not a Bag, so that should use a type check other is Bag prior to attempting to cast. JUnit tests are typically in their own directory, but since this looks like it’s not its own project that might not be manageable.

[dalexander]

Note that there’s a tool in the IDE to automatically generate equals/hashcode which generally does a good job.

[Andreas Sinz]

@alchzh take a look at higher order functions like map, filter and use them instead of all those forEach and local mutable state

[alchzh]

how do map and filter compare performance wise to for loops and forEach?

[Andreas Sinz]

forEach is similar to map etc., they are all inlined functions. The biggest difference between for loops and higher order functions like map is, that the latter creates two additional objects. Both get compiled into a simple while-loop (https://blog.gouline.net/kotlin-bits-for-loops-vs-foreach-30548d7472a5) So the performance is be similar