The Symbol.keyFor(sym)
method retrieves a shared symbol
key from the global symbol registry for the given symbol.
The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.
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
Using keyFor()
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
Browser compatibility
BCD tables only load in the browser