Symbol.keyFor()

The Symbol.keyFor(sym) method retrieves a shared symbol key from the global symbol registry for the given symbol.

Syntax

Symbol.keyFor(sym);

Parameters

sym
Symbol, required. The symbol to find a key for.

Return value

A string representing the key for the given symbol if one is found on the global registry; otherwise, undefined.

Examples

var globalSym = Symbol.for('foo'); // create a new global symbol
Symbol.keyFor(globalSym); // "foo"

var localSym = Symbol();
Symbol.keyFor(localSym); // undefined

// well-known symbols are not symbols registered 
// in the global symbol registry
Symbol.keyFor(Symbol.iterator) // undefined

Specifications

Specification
ECMAScript (ECMA-262)
The definition of 'Symbol.keyFor' in that specification.

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
keyForChrome Full support 40Edge Full support 12Firefox Full support 36IE No support NoOpera Full support 27Safari Full support 9WebView Android Full support 40Chrome Android Full support 40Firefox Android Full support 36Opera Android Full support 27Safari iOS Full support 9Samsung Internet Android Full support 4.0nodejs Full support Yes

Legend

Full support  
Full support
No support  
No support

See also