ebruchez ebruchez - 21 days ago 5
Scala Question

Scala Map implementation keeping entries in insertion order?

In Java, I use

LinkedHashMap
for this purpose. The documentation of Java's
LinkedHashMap
is very clear that it has "predictable iteration order" and I need the same in Scala.

Scala has
ListMap
and
LinkedHashMap
, but the documentation on what they do exactly is poor.

Question: Is Scala's
LinkedHashMap
or
ListMap
the implementation to use for this purpose? If not, what other options are available besides using the Java's
LinkedHashMap
directly?

Answer

From the LinkedHashMap Scaladoc page:

  • "This class implements mutable maps using a hashtable. The iterator and all traversal methods of this class visit elements in the order they were inserted."