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•  package scala

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•  package scalajs

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  scala

•  package js

  Types, methods and values for interoperability with JavaScript libraries.

  Types, methods and values for interoperability with JavaScript libraries.

  This package is only relevant to the Scala.js compiler, and should not be referenced by any project compiled to the JVM.

  Guide

  General documentation on Scala.js is available at http://www.scala-js.org/doc/.

  Overview

  The trait js.Any is the root of the hierarchy of JavaScript types. This package defines important subtypes of js.Any that are defined in the standard library of ECMAScript 5.1 (or ES 6, with a label in the documentation), such as js.Object, js.Array and js.RegExp.

  Implicit conversions to and from standard Scala types to their equivalent in JavaScript are provided. For example, from Scala functions to JavaScript functions and back.

  The most important subtypes of js.Any declared in this package are:

  • js.Object, the superclass of most (all) JavaScript classes
  • js.Array
  • js.Function (and subtraits with specific number of parameters)
  • js.ThisFunction and its subtraits for functions that take the JavaScript this as an explicit parameter
  • js.Dictionary, a Map-like view of the properties of a JS object

  The trait js.Dynamic is a special subtrait of js.Any. It can represent any JavaScript value in a dynamically-typed way. It is possible to call any method and read and write any field of a value of type js.Dynamic.

  There are no explicit definitions for JavaScript primitive types, as one could expect, because the corresponding Scala types stand in their stead:

  • Boolean is the type of primitive JavaScript booleans
  • Double is the type of primitive JavaScript numbers
  • String is the type of primitive JavaScript strings (or null)
  • Unit is the type of the JavaScript undefined value
  • Null is the type of the JavaScript null value

  js.UndefOr gives a scala.Option-like interface where the JavaScript value undefined takes the role of None.

  A | B is an unboxed pseudo-union type, suitable to type values that admit several unrelated types in facade types.

  Definition Classes

  scalajs

•  package annotation

  Definition Classes

  js

•  package timers

  Non-Standard Non-standard, but in general well supported methods to schedule asynchronous execution.

  Non-Standard Non-standard, but in general well supported methods to schedule asynchronous execution.

  The methods in this package work in all JavaScript virtual machines supporting setTimeout and setInterval.

  Definition Classes

  js

•  package typedarray

  ECMAScript 6 The typdearray package provides facade types for JavaScript ArrayBuffer, TypeArrays and DataView.

  ECMAScript 6 The typdearray package provides facade types for JavaScript ArrayBuffer, TypeArrays and DataView. Further, it provides conversions between primitive Scala arrays and TypedArrays

  Definition Classes

  js

• Any
• Array
• ArrayOps
• BigInt
• ConstructorTag
• Date
• Dictionary
• Dynamic
• DynamicImplicits
• Error
• EvalError
• Function
• Function0
• Function1
• Function2
• Iterable
• IterableOps
• Iterator
• JSConverters
• JSConvertersLowPrioImplicits
• JSNumberOps
• JSON
• JSStringOps
• JavaScriptException
• LowPrioAnyImplicits
• LowestPrioAnyImplicits
• Math
• Object
• Promise
• PropertyDescriptor
• RangeError
• ReferenceError
• RegExp
• Symbol
• SyntaxError
• Thenable
• ThisFunction
• ThisFunction0
• ThisFunction1
• ThisFunction2
• Tuple2
• Tuple3
• TypeError
• URIError
• URIUtils
• UndefOrOps
• UnicodeNormalizationForm
• WrappedArray
• WrappedDictionary
• defined
• import
• native
• |

scala.scalajs.js

UndefOrOps 

Companion class UndefOrOps