Question

How to iterate over map keys and values in Scala

Answer 1

val myMap = Map("a" -> 1, "b" -> 2, "c" -> 3)

myMap.foreach { case (key, value) =>
  println(s"Key: $key, Value: $value")
}

  
     
/*
run:
  
Key: a, Value: 1
Key: b, Value: 2
Key: c, Value: 3

*/

 

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Answer 2

val myMap = Map("a" -> 1, "b" -> 2, "c" -> 3)

for ((key, value) <- myMap) {
  println(s"Key: $key, Value: $value")
}

  
     
/*
run:
  
Key: a, Value: 1
Key: b, Value: 2
Key: c, Value: 3

*/

 

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Answer 3

val myMap = Map("a" -> 1, "b" -> 2, "c" -> 3, "d" -> 4)

val transformed = myMap.map { case (key, value) =>
  s"Key: $key, Value: $value"
}

transformed.foreach(println)

  
     
/*
run:
  
Key: a, Value: 1
Key: b, Value: 2
Key: c, Value: 3
Key: d, Value: 4

*/

 

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