This is the documentation for the Scala standard library.
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like Int, Float, Array or Option which are accessible in all Scala compilation units without explicit qualification or imports.
Notable packages include:
scala.collection and its sub-packages contain Scala's collections framework
scala.collection.immutable - Immutable, sequential data-structures such as Vector, List, Range, HashMap or HashSet
scala.collection.mutable - Mutable, sequential data-structures such as ArrayBuffer, StringBuilder, HashMap or HashSet
scala.collection.concurrent - Mutable, concurrent data-structures such as TrieMap
scala.concurrent - Primitives for concurrent programming such as Futures and Promises
scala.io - Input and output operations
scala.math - Basic math functions and additional numeric types like BigInt and BigDecimal
scala.sys - Interaction with other processes and the operating system
scala.util.matching - Regular expressions
Other packages exist. See the complete list on the right.
Additional parts of the standard library are shipped as separate libraries. These include:
scala.reflect - Scala's reflection API (scala-reflect.jar)
scala.xml - XML parsing, manipulation, and serialization (scala-xml.jar)
scala.swing - A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)
Automatic imports
Identifiers in the scala package and the scala.Predef object are always in scope by default.
Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example, List is an alias for scala.collection.immutable.List.
Other aliases refer to classes provided by the underlying platform. For example, on the JVM, String is an alias for java.lang.String.
Definition Classesroot
packagescala
Core Scala types.
Core Scala types. They are always available without an explicit import.