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