Symbol.prototype.toString()
BaselineWidely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
ThetoString() method ofSymbol values returns a string representing this symbol value.
Try it
console.log(Symbol("desc").toString());// Expected output: "Symbol(desc)"console.log(Symbol.iterator.toString());// Expected output: "Symbol(Symbol.iterator)console.log(Symbol.for("foo").toString());// Expected output: "Symbol(foo)"// console.log(Symbol('foo') + 'bar');// Expected output: Error: Can't convert symbol to stringSyntax
toString()Parameters
None.
Return value
A string representing the specified symbol value.
Description
TheSymbol object overrides thetoString method ofObject; it does not inheritObject.prototype.toString(). ForSymbol values, thetoString method returns a descriptive string in the form"Symbol(description)", wheredescription is the symbol'sdescription.
ThetoString() method requires itsthis value to be aSymbol primitive or wrapper object. It throws aTypeError for otherthis values without attempting to coerce them to symbol values.
BecauseSymbol has a[Symbol.toPrimitive]() method, that method always takes priority overtoString() when aSymbol object iscoerced to a string. However, becauseSymbol.prototype[Symbol.toPrimitive]() returns a symbol primitive, and symbol primitives throw aTypeError when implicitly converted to a string, thetoString() method is never implicitly called by the language. To stringify a symbol, you must explicitly call itstoString() method or use theString() function.
Examples
Using toString()
Symbol("desc").toString(); // "Symbol(desc)"// well-known symbolsSymbol.iterator.toString(); // "Symbol(Symbol.iterator)"// global symbolsSymbol.for("foo").toString(); // "Symbol(foo)"Implicitly calling toString()
The only way to make JavaScript implicitly calltoString() instead of[Symbol.toPrimitive]() on a symbol wrapper object is bydeleting the[Symbol.toPrimitive]() method first.
Warning:You should not do this in practice. Never mutate built-in objects unless you know exactly what you're doing.
delete Symbol.prototype[Symbol.toPrimitive];console.log(`${Object(Symbol("foo"))}`); // "Symbol(foo)"Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-symbol.prototype.tostring |