Symbol.prototype.valueOf()
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.
The valueOf() method of Symbol values returns this symbol value.
Try it
const symbol = Symbol("foo");
console.log(typeof Object(symbol));
// Expected output: "object"
console.log(typeof Object(symbol).valueOf());
// Expected output: "symbol"
Syntax
js
valueOf()
Parameters
None.
Return value
The primitive value of the specified Symbol object.
Description
The valueOf() method of Symbol returns the primitive value of a Symbol object as a Symbol data type.
JavaScript calls the valueOf() method to convert an object to a primitive value. You rarely need to invoke the valueOf() method yourself; JavaScript automatically invokes it when encountering an object where a primitive value is expected.
Examples
Using valueOf()
js
const sym = Symbol("example");
sym === sym.valueOf(); // true
Specifications
| Specification |
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| ECMAScript® 2027 Language Specification # sec-symbol.prototype.valueof |
Browser compatibility
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