Symbol.keyFor()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
Die statische Methode Symbol.keyFor()
ruft einen gemeinsamen Symbol
-Schlüssel aus dem globalen Symbol-Register für das angegebene Symbol ab.
Probieren Sie es aus
const globalSym = Symbol.for("foo"); // Global symbol
console.log(Symbol.keyFor(globalSym));
// Expected output: "foo"
const localSym = Symbol(); // Local symbol
console.log(Symbol.keyFor(localSym));
// Expected output: undefined
console.log(Symbol.keyFor(Symbol.iterator));
// Expected output: undefined
Syntax
js
Symbol.keyFor(sym)
Parameter
sym
-
Symbol, erforderlich. Das Symbol, für das ein Schlüssel gefunden werden soll.
Rückgabewert
Ein String, der den Schlüssel des angegebenen Symbols im globalen Register darstellt, falls dieser vorhanden ist; andernfalls undefined
.
Beispiele
Verwendung von keyFor()
js
const globalSym = Symbol.for("foo"); // create a new global symbol
Symbol.keyFor(globalSym); // "foo"
const localSym = Symbol();
Symbol.keyFor(localSym); // undefined
// well-known symbols are not symbols registered
// in the global symbol registry
Symbol.keyFor(Symbol.iterator); // undefined
Spezifikationen
Specification |
---|
ECMAScript® 2025 Language Specification # sec-symbol.keyfor |
Browser-Kompatibilität
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keyFor |
Legend
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- Full support
- Full support
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