Type Members

1.  trait Any extends AnyRef

   Root of the hierarchy of JavaScript types.

   Root of the hierarchy of JavaScript types.

   Subtypes of js.Any are JavaScript types, which have different semantics and guarantees than Scala types (subtypes of AnyRef and AnyVal). Operations on JavaScript types behave as the corresponding operations in the JavaScript language.

   You can implement JavaScript types in Scala.js. The implementation (i.e., the method and constructor bodies) will follow Scala semantics, but the constructor and methods will be called using JavaScript semantics (e.g., runtime dispatch).

   A JavaScript type that is annotated with @js.native is a facade type to APIs implemented in JavaScript code. Its implementation is irrelevant and never emitted. As such, all members must be defined with their right-hand-side being js.native. Further, native JavaScript types must be annotated with one of @JSGlobal, @JSImport, @JSGlobalScope to specify where to fetch it from.

   In most cases, you should not directly extend this trait, but rather extend js.Object.

   It is not possible to define traits or classes that inherit both from this trait and a strict subtype of AnyRef. In fact, you should think of js.Any as a third direct subclass of scala.Any, besides scala.AnyRef and scala.AnyVal.

   See the JavaScript interoperability guide of Scala.js for more details.

   Annotations

   @JSType()

2.  class Array[A] extends Object with Iterable[A]

   Arrays are list-like objects whose prototype has methods to perform traversal and mutation operations.

   Arrays are list-like objects whose prototype has methods to perform traversal and mutation operations. Neither the length of a JavaScript array nor the types of its elements are fixed. Since an array's size length grow or shrink at any time, JavaScript arrays are not guaranteed to be dense. In general, these are convenient characteristics; but if these features are not desirable for your particular use, you might consider using typed arrays.

   MDN

   To construct a new array with uninitialized elements, use the constructor of this class. To construct a new array with specified elements, as if you used the array literal syntax in JavaScript, use the Array.apply method instead.

   A

   Type of the elements of the array

   Annotations

   @JSType() @native() @JSGlobal()

3.  final class ArrayOps[A] extends ArrayLike[A, Array[A]] with Builder[A, Array[A]]

   Equivalent of scm.ArrayOps for js.Array.

   Equivalent of scm.ArrayOps for js.Array.

   Annotations

   @inline()

4.  final class BigInt extends Object

   ECMAScript 2019

   ECMAScript 2019

   A built-in object that provides a way to represent whole numbers larger than 2 ^ 53 - 1, which is the largest number JavaScript can reliably represent with the Number primitive.

   BigInt can be used for arbitrarily large integers.

   Annotations

   @JSType() @native() @JSGlobal()

   See also

   https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt

5.  final class ConstructorTag[T <: Any] extends AnyVal

   Stores the JS constructor function of a JS class.

   Stores the JS constructor function of a JS class.

   A ConstructorTag[T] holds the constructor function of a JS class, as retrieved by js.constructorOf[T]. Similarly to ClassTags, ConstructorTags can be implicitly materialized when T is statically known to be a JS class, i.e., a valid type argument to js.constructorOf.

6.  class Date extends Object

   Creates a JavaScript Date instance that represents a single moment in time.

   Creates a JavaScript Date instance that represents a single moment in time. Date objects are based on a time value that is the number of milliseconds since 1 January, 1970 UTC.

   MDN

   Annotations

   @JSType() @native() @JSGlobal()

   Note

   js.Date objects can represent an *invalid date*, for example, if they are constructed from a String that cannot be parsed as a date. Most methods of such a js.Date will return NaN (for those returning a Double) or other invalid values.

7.  sealed trait Dictionary[A] extends Any

   Dictionary "view" of a JavaScript value.

   Dictionary "view" of a JavaScript value.

   Using objects as dictionaries (maps from strings to values) through their properties is a common idiom in JavaScript. This trait lets you treat an object as such a dictionary, with the familiar API of a Map.

   To use it, cast your object, say x, into a Dictionary using

   val xDict = x.asInstanceOf[js.Dictionary[Int]]

   then use it as

   xDict("prop") = 5
   println(xDict.get("prop")) // displays Some(5)
   xDict -= "prop"            // removes the property "prop"
   println(xDict.get("prop")) // displays None

   To enumerate all the keys of a dictionary, use collection methods or for comprehensions. For example:

   for ((prop, value) <- xDict) {
     println(prop + " -> " + value)
   }

   Note that this does not enumerate properties in the prototype chain of xDict.

   This trait extends js.Any directly, because it is not safe to call methods of js.Object on it, given that the name of these methods could be used as keys in the dictionary.

   Annotations

   @JSType()

8.  sealed trait Dynamic extends Any with scala.Dynamic

   Dynamically typed JavaScript value.

   Dynamically typed JavaScript value.

   Values of this trait accept all possible JavaScript operations in a dynamically typed way. You can read and write any field, call any method, apply any JavaScript operator to values of this type.

   Annotations

   @JSType() @native()

9.  class Error extends Object

   Annotations

   @JSType() @native() @JSGlobal()

10.  class EvalError extends Error

    An instance representing an error that occurs regarding the global function eval().

    An instance representing an error that occurs regarding the global function eval().

    MDN

    Annotations

    @JSType() @native() @JSGlobal()

11.  class Function extends Object

    The Function constructor creates a new Function object.

    The Function constructor creates a new Function object. In JavaScript every function is actually a Function object.

    Function objects created with the Function constructor are parsed when the function is created. This is less efficient than declaring a function and calling it within your code, because functions declared with the function statement are parsed with the rest of the code.

    All arguments passed to the function are treated as the names of the identifiers of the parameters in the function to be created, in the order in which they are passed.

    Note: Functions created with the Function constructor do not create closures to their creation contexts; they always are created in the global scope. When running them, they will only be able to access their own local variables and global ones, not the ones from the scope in which the Function constructor was called. This is different from using eval with code for a function expression.

    Invoking the Function constructor as a function (without using the new operator) has the same effect as invoking it as a constructor.

    MDN

    Annotations

    @JSType() @native() @JSGlobal()

12.  trait Function0[+R] extends Function

    Annotations

    @JSType() @native()

13.  trait Function1[-T1, +R] extends Function

    Annotations

    @JSType() @native()

14.  trait Function2[-T1, -T2, +R] extends Function

    Annotations

    @JSType() @native()

15.  trait Iterable[+A] extends Object

    ECMAScript 6 JavaScript Iterable.

    ECMAScript 6 JavaScript Iterable.

    Annotations

    @JSType()

16.  final class IterableOps[+A] extends collection.Iterable[A]

    Adapts a JavaScript Iterable to a Scala Iterable

    Adapts a JavaScript Iterable to a Scala Iterable

    Annotations

    @inline()

17.  trait Iterator[+A] extends Object

    ECMAScript 6 JavaScript Iterator.

    ECMAScript 6 JavaScript Iterator.

    Annotations

    @JSType()

18.  sealed abstract class JSConvertersLowPrioImplicits extends AnyRef
19.  trait JSNumberOps extends Any

    Operations on JavaScript numbers.

    Operations on JavaScript numbers.

    Annotations

    @JSType()

20.  trait JSStringOps extends Any

    Operations on JavaScript strings.

    Operations on JavaScript strings.

    The methods with an equivalent signature in String but with a different meaning are prefixed by js in this trait.

    Annotations

    @JSType()

21.  final case class JavaScriptException(exception: scala.Any) extends RuntimeException with Product with Serializable
22.  sealed trait LowPrioAnyImplicits extends LowestPrioAnyImplicits
23.  sealed trait LowestPrioAnyImplicits extends AnyRef
24.  class Object extends Any

    Base class of all JavaScript objects.

    Base class of all JavaScript objects.

    Annotations

    @JSType() @native() @JSGlobal()

25.  class Promise[+A] extends Object with Thenable[A]

    ECMAScript 6 Promise of an asynchronous result.

    ECMAScript 6 Promise of an asynchronous result.

    Attention! The nature of this class, from the ECMAScript specification, makes it inherently un-typeable, because it is not type parametric.

    The signatures of the constructor and the methods then and catch are only valid provided that the values of A and B are not Thenables.

    We recommend to use Scala's Futures instead of Promise as much as possible. A Promise can be converted to a Future with .toFuture and back with .toJSPromise (provided by JSConverters).

    With

    import scala.scalajs.js.Thenable.Implicits._

    you can implicitly convert a Promise to a Future, and therefore you can directly use the methods of Future on Promises.

    Annotations

    @JSType() @native() @JSGlobal()

26.  trait PropertyDescriptor extends Object

    Annotations

    @JSType()

27.  class RangeError extends Error

    An instance representing an error that occurs when a numeric variable or parameter is outside of its valid range.

    An instance representing an error that occurs when a numeric variable or parameter is outside of its valid range.

    A RangeError is thrown when trying to pass a number as an argument to a function that does not allow a range that includes that number. This can be encountered when to create an array of an illegal length with the Array constructor, or when passing bad values to the numeric methods toExponential, toFixed, or toPrecision.

    MDN

    Annotations

    @JSType() @native() @JSGlobal()

28.  class ReferenceError extends Error

    Represents an error when a non-existent variable is referenced.

    Represents an error when a non-existent variable is referenced.

    A ReferenceError is thrown when trying to dereference a variable that has not been declared.

    MDN

    Annotations

    @JSType() @native() @JSGlobal()

29.  class RegExp extends Object

    The RegExp constructor creates a regular expression object for matching text with a pattern.

    The RegExp constructor creates a regular expression object for matching text with a pattern.

    MDN

    Annotations

    @JSType() @native() @JSGlobal()

30.  sealed trait Symbol extends Any

    ECMAScript 6 JavaScript Symbol.

    ECMAScript 6 JavaScript Symbol.

    Annotations

    @JSType() @native()

31.  class SyntaxError extends Error

    Represents an error when trying to interpret syntactically invalid code.

    Represents an error when trying to interpret syntactically invalid code.

    A SyntaxError is thrown when the JavaScript engine encounters tokens or token order that does not conform to the syntax of the language when parsing code.

    MDN

    Annotations

    @JSType() @native() @JSGlobal()

32.  trait Thenable[+A] extends Object

    A thing on which one can call the then method.

    A thing on which one can call the then method.

    Thenables are automatically transitively flattened by the then method of Thenables. In particular, this is true for Promises.

    Attention! The nature of this interface, from the ECMAScript specification, makes it inherently un-typeable, because it is not type parametric.

    The signature of the then method is only valid provided that the values of B do not have a then method.

    Annotations

    @JSType()

33.  trait ThisFunction extends Function

    A JavaScript function where this is considered as a first parameter.

    A JavaScript function where this is considered as a first parameter.

    Annotations

    @JSType()

    See also

    Calling JavaScript from Scala.js

34.  trait ThisFunction0[-T0, +R] extends Function with ThisFunction

    Annotations

    @JSType() @native()

35.  trait ThisFunction1[-T0, -T1, +R] extends Function with ThisFunction

    Annotations

    @JSType() @native()

36.  trait ThisFunction2[-T0, -T1, -T2, +R] extends Function with ThisFunction

    Annotations

    @JSType() @native()

37.  sealed trait Tuple2[+T1, +T2] extends Object

    A tuple "view" of 2 elements of a JavaScript js.Array.

    A tuple "view" of 2 elements of a JavaScript js.Array.

    Supports implicit conversions to and from scala.Tuple2.

    To use it, cast your array into a js.Tuple2 using

    val array = js.Array[Any](42, "foobar")
    val tuple2 = array.asInstanceOf[js.Tuple2[Int, String]]

    or convert a Scala tuple

    val obj: js.Tuple2[Int, String] = (42, "foobar")

    Annotations

    @JSType()

38.  sealed trait Tuple3[+T1, +T2, +T3] extends Object

    A tuple "view" of 3 elements of a JavaScript js.Array.

    A tuple "view" of 3 elements of a JavaScript js.Array.

    Annotations

    @JSType()

    See also

    js.Tuple2

39.  class TypeError extends Error

    Represents an error when a value is not of the expected type.

    Represents an error when a value is not of the expected type.

    A TypeError is thrown when an operand or argument passed to a function is incompatible with the type expected by that operator or function.

    MDN

    Annotations

    @JSType() @native() @JSGlobal()

40.  class URIError extends Error

    Represents an error when a malformed URI is encountered.

    Represents an error when a malformed URI is encountered.

    A URIError is thrown when the URI handling functions are passed a malformed URI.

    MDN

    Annotations

    @JSType() @native() @JSGlobal()

41.  type UndefOr[+A] = |[A, Unit]

    Value of type A or the JS undefined value.

    Value of type A or the JS undefined value.

    This type is actually strictly equivalent to A | Unit, since Unit is the type of the undefined value.

    js.UndefOr[A] is the type of a value that can be either undefined or an A. It provides an API similar to that of scala.Option through the UndefOrOps implicit class, where undefined take the role of None.

    By extension, this type is also suited to typing optional fields in native JS types, i.e., fields that may not exist on the object.

42.  final class UndefOrOps[A] extends AnyVal

43.  sealed trait UnicodeNormalizationForm extends Any

    A Unicode Normalization Form.

    A Unicode Normalization Form.

    Annotations

    @JSType()

    See also

    js.JSStringOps.normalize

    Unicode Normalization Forms

44.  final class WrappedArray[A] extends AbstractBuffer[A] with GenericTraversableTemplate[A, WrappedArray] with collection.mutable.IndexedSeq[A] with BufferLike[A, WrappedArray[A]] with ArrayLike[A, WrappedArray[A]] with Builder[A, WrappedArray[A]]

    Equivalent of scm.WrappedArray for js.Array.

    Equivalent of scm.WrappedArray for js.Array.

    Annotations

    @inline()

45.  final class WrappedDictionary[A] extends AbstractMap[String, A] with Map[String, A] with MapLike[String, A, WrappedDictionary[A]]

    Wrapper to use a js.Dictionary as a scala.mutable.Map

    Wrapper to use a js.Dictionary as a scala.mutable.Map

    Annotations

    @inline()

46.  class native extends Annotation with StaticAnnotation

    Marks the annotated class, trait or object as a native JS entity.

    Marks the annotated class, trait or object as a native JS entity.

    Native JS entities are not implemented in Scala.js. They are facade types for native JS libraries.

    Only types extending js.Any can be annotated with @js.native. The body of all concrete members in a native JS class, trait or object must be = js.native.

47.  sealed trait |[A, B] extends AnyRef

    Value of type A or B (union type).

    Value of type A or B (union type).

    Scala does not have union types, but they are important to many interoperability scenarios. This type provides a (partial) encoding of union types using implicit evidences.

    Annotations

    @JSType()