Class Symbol

• Object
  • Symbol

Symbol is a primitive data type that can serve as object properties. Symbol instance can be created explicitly or via a global registry, see for(String).

API Versioned:

From version 21.2.

Constants

hasInstance : Symbol

The symbol used by instanceof.

isConcatSpreadable : Symbol

The symbol used by Array.concat(Object...).

iterator : Symbol

The symbol used by for...of.

match : Symbol

The symbol used by String.match(RegExp).

replace : Symbol

The symbol used by String.replace().

search : Symbol

The symbol used by String.search(RegExp).

species : Symbol

The symbol used to create derived objects.

split : Symbol

The symbol used by String.split().

toPrimitive : Symbol

The symbol used to convert an object to a primitive value.

toStringTag : Symbol

The symbol used by Object.toString().

unscopables : Symbol

The symbol used by with.

Properties

Constructor Summary

Symbol()

Creates a new symbol.

Symbol(description : String)

Creates a new symbol.

Method Summary

static for(key : String) : Symbol

Obtains a symbol from the global registry.

static keyFor(symbol : Symbol) : String

Returns the key within the global symbol registry under which the given symbol is stored.

Methods inherited from class Object

assign, create, create, defineProperties, defineProperty, entries, freeze, fromEntries, getOwnPropertyDescriptor, getOwnPropertyNames, getOwnPropertySymbols, getPrototypeOf, hasOwnProperty, is, isExtensible, isFrozen, isPrototypeOf, isSealed, keys, preventExtensions, propertyIsEnumerable, seal, setPrototypeOf, toLocaleString, toString, valueOf, values

Constructor Detail

Symbol

publicSymbol()

Creates a new symbol. Note that it must be called without new. Symbols created via this method are always distinct.

Symbol

publicSymbol(description : String)

Creates a new symbol. Note that it must be called without new. Symbols created via this method are always distinct.

Parameters:

description - A description for this symbol.

Method Detail

for

static for(key : String) : Symbol

Obtains a symbol from the global registry. If no symbol exists for the key within the registry a new symbol is created and stored in the global registry.

API Versioned:

From version 21.2.

Parameters:

key - The key for a symbol within the global registry.

Returns:

The found or newly created symbol.

keyFor

static keyFor(symbol : Symbol) : String

Returns the key within the global symbol registry under which the given symbol is stored.

Parameters:

symbol - The symbol to look for.

Returns:

The key for the given symbol if the symbol is known to the global registry, else return undefined.