I’m following this code along with the debugger, and I’m very confused as to when or why `head` ends...

# getting-started

[oday]

I’m following this code along with the debugger, and I’m very confused as to when or why head ends up changing and pointing to new elements
https://paste.ofcode.org/3h6juagTuPwvZaDEeTkwCP

[oday]

when an element is found to be inside the elements set, that element is removed from the list

[oday]

like why does reassigning current also reassign head

[oday]

if I assign head to something, that something is now head?

[oday]

so its pass by value

[Sourabh Rawat]

can you provide an input where head is getting reassigned?

[oday]

yea any list of Node(2, Node(3, Node(4, Node(5))))

[oday]

it ends up reversing the list correctly

[oday]

how does head come out changed in the end? its really confusing

[Sourabh Rawat]

https://pl.kotl.in/FTMbmo_3a
isnt this expected?

[oday]

sure, but inside the function I am expecting to at least see some line that assigns current back to head ? I dunno why to expect that but I guess this is because function parameters are always val so you need to grab a reference to them to work with it

[oday]

is this not the same as above?

fun main(){
   val variable = 100
   println(test(variable))
}

fun test(testValue: Int): Int {
    var temp = testValue

    temp = 98

    return testValue
}

result should be 98 now

[oday]

took the value of testValue assigned it to a temp, changed the temp, returned testvalue

[Sourabh Rawat]

Ill try to explain. Might not be the best explanation.
head will never be changed, although it's next value can be changed(in the while loop). Since for removing duplicates you won't be removing the first element, only second and so on. thats why they are just returning head.
In fact, they don't even need to return the head from the function, as it will always refer to same node object as the passed head to the function.

[oday]

aha!

[oday]

and yes that is true about not needing to return head, I added that myself because I thought how come it looks like a no-op

[oday]

ok thanks a lot