object OptionConverters
This object contains methods that convert between Scala Option
and Java Optional
types.
The explicit conversion methods defined here are intended to be used in Java code. For Scala code, it is recommended to use the extension methods defined in scala.jdk.OptionConverters.
- Source
- OptionConverters.scala
- Alphabetic
- By Inheritance
- OptionConverters
- AnyRef
- Any
- Hide All
- Show All
- Public
- All
Value Members
- def toJava[A](o: Option[A]): Optional[A]
Convert a Scala
Option
to a JavaOptional
- def toJavaOptionalDouble(o: Option[java.lang.Double]): OptionalDouble
Convert a Scala
Option[java.lang.Double]
to a JavaOptionalDouble
Convert a Scala
Option[java.lang.Double]
to a JavaOptionalDouble
Note: this method uses the boxed type
java.lang.X
instead of the primitive typescala.X
to improve compatibility when using it in Java code (the Scala compiler emitsC[Int]
asC[Object]
in bytecode due to scala/bug#4214). In Scala code, addimport scala.jdk.OptionConverters._
and use the extension methods instead. - def toJavaOptionalInt(o: Option[Integer]): OptionalInt
Convert a Scala
Option[java.lang.Integer]
to a JavaOptionalInt
Convert a Scala
Option[java.lang.Integer]
to a JavaOptionalInt
Note: this method uses the boxed type
java.lang.X
instead of the primitive typescala.X
to improve compatibility when using it in Java code (the Scala compiler emitsC[Int]
asC[Object]
in bytecode due to scala/bug#4214). In Scala code, addimport scala.jdk.OptionConverters._
and use the extension methods instead. - def toJavaOptionalLong(o: Option[java.lang.Long]): OptionalLong
Convert a Scala
Option[java.lang.Long]
to a JavaOptionalLong
Convert a Scala
Option[java.lang.Long]
to a JavaOptionalLong
Note: this method uses the boxed type
java.lang.X
instead of the primitive typescala.X
to improve compatibility when using it in Java code (the Scala compiler emitsC[Int]
asC[Object]
in bytecode due to scala/bug#4214). In Scala code, addimport scala.jdk.OptionConverters._
and use the extension methods instead. - def toScala(o: OptionalLong): Option[java.lang.Long]
Convert a Java
OptionalLong
to a ScalaOption[java.lang.Long]
Convert a Java
OptionalLong
to a ScalaOption[java.lang.Long]
Note: this method uses the boxed type
java.lang.X
instead of the primitive typescala.X
to improve compatibility when using it in Java code (the Scala compiler emitsC[Int]
asC[Object]
in bytecode due to scala/bug#4214). In Scala code, addimport scala.jdk.OptionConverters._
and use the extension methods instead. - def toScala(o: OptionalInt): Option[Integer]
Convert a Java
OptionalInt
to a ScalaOption[java.lang.Integer]
Convert a Java
OptionalInt
to a ScalaOption[java.lang.Integer]
Note: this method uses the boxed type
java.lang.X
instead of the primitive typescala.X
to improve compatibility when using it in Java code (the Scala compiler emitsC[Int]
asC[Object]
in bytecode due to scala/bug#4214). In Scala code, addimport scala.jdk.OptionConverters._
and use the extension methods instead. - def toScala(o: OptionalDouble): Option[java.lang.Double]
Convert a Java
OptionalDouble
to a ScalaOption[java.lang.Double]
Convert a Java
OptionalDouble
to a ScalaOption[java.lang.Double]
Note: this method uses the boxed type
java.lang.X
instead of the primitive typescala.X
to improve compatibility when using it in Java code (the Scala compiler emitsC[Int]
asC[Object]
in bytecode due to scala/bug#4214). In Scala code, addimport scala.jdk.OptionConverters._
and use the extension methods instead. - def toScala[A](o: Optional[A]): Option[A]
Convert a Java
Optional
to a ScalaOption
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int
,Float
,Array
orOption
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 frameworkscala.collection.immutable
- Immutable, sequential data-structures such asVector
,List
,Range
,HashMap
orHashSet
scala.collection.mutable
- Mutable, sequential data-structures such asArrayBuffer
,StringBuilder
,HashMap
orHashSet
scala.collection.concurrent
- Mutable, concurrent data-structures such asTrieMap
scala.concurrent
- Primitives for concurrent programming such asFutures
andPromises
scala.io
- Input and output operationsscala.math
- Basic math functions and additional numeric types likeBigInt
andBigDecimal
scala.sys
- Interaction with other processes and the operating systemscala.util.matching
- Regular expressionsOther 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.collection.parallel
- Parallel collections (scala-parallel-collections.jar)scala.util.parsing
- Parser combinators (scala-parser-combinators.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 forscala.collection.immutable.List
.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
String
is an alias forjava.lang.String
.