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Symbol.prototype.toString()

The toString() method of Symbol values returns a string representing this symbol value.

Try it

Syntax

toString()

Parameters

None.

Return value

A string representing the specified symbol value.

Description

The Symbol object overrides the toString method of Object; it does not inherit Object.prototype.toString(). For Symbol values, the toString method returns a descriptive string in the form "Symbol(description)", where description is the symbol's description.

The toString() method requires its this value to be a Symbol primitive or wrapper object. It throws a TypeError for other this values without attempting to coerce them to symbol values.

Because Symbol has a [@@toPrimitive]() method, that method always takes priority over toString() when a Symbol object is coerced to a string. However, because Symbol.prototype[@@toPrimitive]() returns a symbol primitive, and symbol primitives throw a TypeError when implicitly converted to a string, the toString() method is never implicitly called by the language. To stringify a symbol, you must explicitly call its toString() method or use the String() function.

Examples

Using toString()

Symbol("desc").toString(); // "Symbol(desc)"

// well-known symbols
Symbol.iterator.toString(); // "Symbol(Symbol.iterator)"

// global symbols
Symbol.for("foo").toString(); // "Symbol(foo)"

Implicitly calling toString()

The only way to make JavaScript implicitly call toString() instead of [@@toPrimitive]() on a symbol wrapper object is by deleting the @@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 Language Specification # sec-symbol.prototype.tostring

Browser compatibility

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	Deno	Node.js
`toString`	38	12	36	25	9	38	36	25	9	3.0	38	1.0	0.12.0