Kotlin: How to write nested loops in functional way?

Question

What could be an alternate way to print the cells of a table other than using a nested loop.

for(i in 1..2){
  for(j in 1..2){
      println("$i,$j")
  }
}

Any approach using Pairs?

Using pairs isn’t a better approach because then you’re instantiating a bunch of objects. — Tenfour04
– Tenfour04, Commented Jun 15, 2020 at 12:34
Yes you are right. Better isn't the right word here, I''ll change it to alternate :P. It's become habitual for me to consider kotlin-ized code better, which is obviously not the case always. — Vandit Goel
– Vandit Goel, Commented Jul 28, 2020 at 14:18

sidgate · Accepted Answer · 2020-06-15 11:23:42Z

3

You can use map/flatMap to convert the ranges to list of Pairs

val pairs = (1..2).flatMap { i -> (1..2).map { j -> i to j } }
pairs.forEach { println("${it.first},${it.second} ") }

answered Jun 15, 2020 at 11:23

sidgate

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1 Comment

Thanks! That's what I was looking for