CODEWITHSUNDEEP
scala
Ivan
Ivan

Reputation: 64207

Can I yield or map one element into many in Scala?

val inArray = Array("a", "b", "c", "d")
// ...
val outArray = Array("a1", "a2", "a3", "b1", "b2", "b3", "c1", "c2", "c3", "d1", "d2", "d3")

How to map inArray to outArray?

The idea is to iterate through inArray yielding 3 elements (by concatenating an index in this example) from each of its elements.

Upvotes: 7

Views: 2750

Answers (3)

oxbow_lakes
oxbow_lakes

Reputation: 134260

This can look better using a for-comprehension

for {
  s <- inArray
  i <- Array(1, 2, 3) //or other traversable
} 
yield s + i

This uses a combination of map and flatMap under the covers as described in detail in the SLS

Upvotes: 7

Kim Stebel
Kim Stebel

Reputation: 42037

You can do that with flatMap.

inArray.flatMap(c => (1 to 3).map(c+))

Upvotes: 13

missingfaktor
missingfaktor

Reputation: 92016

Using for-comprehension.

scala> for {
     |   x <- Array("a", "b", "c", "d")
     |   n <- 1 to 3
     | } yield x + n
res0: Array[java.lang.String] = Array(a1, a2, a3, b1, b2, b3, c1, c2, c3, d1, d2, d3)

Upvotes: 5

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