Class Symbol

• TopLevel.Object
  • TopLevel.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 Version:

Available from version 21.2.

Note

Constant Summary 

Constant	Description
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.

Constructor Summary 

Constructor	Description
Symbol()	Creates a new symbol.
Symbol(String)	Creates a new symbol.

Method Summary 

Method	Description
static for(String)	Obtains a symbol from the global registry.
static keyFor(Symbol)	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

Constant Details 

hasInstance 

hasInstance: Symbol

The symbol used by instanceof.

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isConcatSpreadable 

isConcatSpreadable: Symbol

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

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iterator 

iterator: Symbol

The symbol used by for...of.

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match 

match: Symbol

The symbol used by String.match(RegExp).

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replace 

replace: Symbol

The symbol used by String.replace().

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search 

search: Symbol

The symbol used by String.search(RegExp).

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species 

species: Symbol

The symbol used to create derived objects.

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split 

split: Symbol

The symbol used by String.split().

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toPrimitive 

toPrimitive: Symbol

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

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toStringTag 

toStringTag: Symbol

The symbol used by Object.toString().

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unscopables 

unscopables: Symbol

The symbol used by with.

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Constructor Details 

Symbol() 

Symbol()

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

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Symbol(String) 

Symbol(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.

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Method Details 

for(String) - Variant 1 

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.

Parameters:

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

Returns:

• The found or newly created symbol.

API Version:

Available from version 21.2.

Note

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keyFor(Symbol) 

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.

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