A Collections framework provides data structures for collecting one or more values of a given type such as arrays, lists, maps, sets, and trees. Most of the popular programming languages have their own collections framework (or, at the least lists and maps) as these data structures are the building blocks of modern software projects.
  • Scala's collections also have higher-order operations like map, filter, and reduce that make it possible to manage and manipulate data with short and expressive expressions.
  • It also has separate Mutable versus Immutable collection type hierarchies which make switching between immutable data (for stability) and mutable data (when necessary) convenient.
  • As much as possible we should make use of immutable collections
Scala Immutable Collection API
Scala Mutable Collection API