Which iteration construct is better to use in Scala?

Question

Recently, I started coding many of my Scala programming competitions. (Here you can take a look at the platform - http://codeforces.com/ )

Regarding the nature of the problems, I often have to iterate over an array or over input. For instance. There is an expression about the problem, which said that on the first line of input I will get the number M, and then I need to read M lines or integers or whatever. I am trying to use a different approach for this:

for (i <- 0 until M)
---- 
(0 until M).foreach
----
var i = 0
while (i < M)
---

Or even tail recursion

@tailrec
  def recursion(i: Int): Unit = {
    if (i < M) {
      doSomething()
      recursion(i + 1)
    }
  }

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Answer 1

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johanandren.

Answer 2

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