How can I convert immutable.Map to mutable.Map in Scala?

by

The cleanest way would be to use the mutable.Map varargs factory. Unlike the ++ approach, this uses the CanBuildFrom mechanism, and so has the potential to be more efficient if library code was written to take advantage of this:

val m = collection.immutable.Map(1->"one",2->"Two")
val n = collection.mutable.Map(m.toSeq: _*)

This works because a Map can also be viewed as a sequence of Pairs.

More Related Contents:

  1. Scala 2.8 breakOut
  2. What is a “context bound” in Scala?
  3. What do
  4. Is the Scala 2.8 collections library a case of “the longest suicide note in history”? [closed]
  5. How to write to a file in Scala?
  6. Scala 2.8 collections design tutorial
  7. Scala Map implementation keeping entries in insertion order?
  8. Scala pattern matching with lowercase variable name
  9. When to use parenthesis in Scala infix notation
  10. Implementing yield (yield return) using Scala continuations
  11. How do I make a function involving futures tail recursive?
  12. Use functional combinators on Scala Tuples?
  13. Overload constructor for Scala’s Case Classes?
  14. What are Scala continuations and why use them?
  15. When is @uncheckedVariance needed in Scala, and why is it used in GenericTraversableTemplate?
  16. Scala best way of turning a Collection into a Map-by-key?
  17. What is the eta expansion in Scala?
  18. How to split a dataframe into dataframes with same column values?
  19. How to use regex to include/exclude some input files in sc.textFile?
  20. How to find spark RDD/Dataframe size?
  21. What’s the easiest way to use reify (get an AST of) an expression in Scala?
  22. Doing something before or after all Scalatest tests
  23. Provide schema while reading csv file as a dataframe in Scala Spark
  24. Error with varargs for function-objects in Scala?
  25. How do you define a local var/val in the primary constructor in Scala?
  26. Scala 2.10 reflection, how do I extract the field values from a case class, i.e. field list from case class
  27. assembly-merge-strategy issues using sbt-assembly
  28. Understanding the Aux pattern in Scala Type System
  29. Multiple parameter closure argument type not inferred
  30. How to create a Dataset of Maps?

Leave a Comment