is there a cool new flashy kotlin way to iterate over 2 list kotlinlang #getting-started

08/01/2017, 10:43 AM

is there a cool new flashy kotlin way to iterate over 2 lists of the same size in Kotlin?

08/01/2017, 10:44 AM

zip

08/01/2017, 10:44 AM

zip…ok I’ll look into it, makes them into 1 list that you can iterate over?

08/01/2017, 10:45 AM

map elements at the same index to a pair and then you can iterate as usual

08/01/2017, 10:46 AM

but how do I pick first or second

to access the properties of the objects? isnt first referring to the first of the pair and second to the second>

08/01/2017, 10:46 AM

first

second

08/01/2017, 10:46 AM

08/01/2017, 10:47 AM

Or you could destructure. Something like:

val a = listOf("a", "b")
    val b = listOf("c", "d")
    a.zip(b).forEach { (first, second) -> print(first + second) }

Whatever works for you man

08/01/2017, 10:48 AM

I add “Pipe” object which has these params, and i use those pipes to draw them with a drawRect

allPipes.forEach {
      canvas?.drawRect(it.first.distanceX, it.distanceY, it.width,
          it.height, painter)
    }

do I have to have now two drawRects? one including `first`‘s params and the other including `second`‘s params?

08/01/2017, 10:49 AM

I don't follow

08/01/2017, 10:50 AM

it’s a class

Pipe

which has right left top bottom params, i fill up an array of Pipes and then draw them

I want to draw bottom pipes and top pipes, so 2 arrays joined into the

allPipes

i iterate over it and feed the objects to drawRect, to be drawn

if I always use

first

in the loop, I will always get the first of each pair, not both, i want both, so I use two drawRect calls

yep, it works

08/01/2017, 10:52 AM

out of curiosity, why do you have one list for bottom and another for top pipes?

08/01/2017, 10:52 AM

hmm well to make them bottom, their param values have to change

yea i can do a even/odd check inside 1 loop and change the params depending on what I want

lol, yea that’s better