Question

How to iterate over a HashMap in Scala

Answer 1

import scala.collection.mutable.HashMap

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

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



/*
run:

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

 

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Answer 2

import scala.collection.mutable.HashMap

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

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



/*
run:

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

 

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Answer 3

import scala.collection.mutable.HashMap

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

// Iterating over keys
for (key <- map.keys) {
  println(s"Key: $key")
}

// Iterating over values
for (value <- map.values) {
  println(s"Value: $value")
}


/*
run:

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

 

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