yes

# getting-started

[kaizo]

yes

[Hamza]

what have you tried

[kaizo]

val result = list1.intersect(list2)

[kaizo]

some lamnba too, but i'm not confortable with those again

[marstran]

If you want all elements that are not common between the two lists, you could do list1.union(list2) - list1.intersect(list2)

[kaizo]

I need to find the first term of the second list that match the first list

[kaizo]

ur 'sugestion give me the element of list 2 that aren't in list1, right?

[Hamza]

why dont u try it out

[kaizo]

I've just try it

[kaizo]

it give me number that aren't in the first list

[kaizo]

I 'v tought that ther was a kotlin way with lanmbda to do this

[kaizo]

i'll keep looking

[kaizo]

thx

[marstran]

The code above gives all elements of list1 which are not in list2, and all elements in list2 which are not in list1.

[kaizo]

yes, I saw that but that 's not what I need ^^

[Alowaniak]

It sounds as if you do want a.intersect(b) except maybe only the first element of that result?

[kaizo]

yes I think u've got the idea 🙂

[kaizo]

var result: Long = 0
    for (element in r1) {
        for (element2 in r2) {
            if (element2 == element)
                result=element2
            break
        }

    }
    return result

[kaizo]

I've done this, it's working but but not pretty ^^

[Alowaniak]

well yea so you want a.intersect(b)[0]

[kaizo]

I found

a.intersect(b).first()

[kaizo]

it's working too

[kaizo]

thx!

[Alowaniak]

ah yea [0] probably doesn't even work depending on what types I guess; np

[kaizo]

nope [0] doesn't work but . first() is ^^

[kaizo]

so much better than my horrible loops 😂

[Alowaniak]

Note that you'll get a NoSuchElementException if it's empty though, you might want to do a.intersect(b).firstOrNull() ?: 0 (to match your loops) or whatever you want as default value

(Oh and btw for multiline code in slack use triple `)

[kaizo]

thx a lot 👍

[ilya.gorbunov]

If you want just the first item that is in both a and b, it would be more efficient to use
a.first { it in b } (or firstOrNull)

[kaizo]

thx! lambda are so obvious when I read it, but I still need to practice them 😁