Symbol

The Symbol Constructor

Symbol ( [ description ] )

1. If NewTarget is not undefined, throw a TypeError exception.
2. Note: the Symbol Constructor is not intended to be used with the new operator(not the target for new)
3. If description is undefined, let descString be undefined; Else, let descString be ? ToString(description).
4. Return a new unique Symbol value whose [[Description]] value is descString.
5. Note: the Symbol() function returns a Symbol type instead of a Symbol object

Symbol Prototype Object

abstract operation thisSymbolValue(value)

1. If Type(value) is Symbol, return value.
2. If Type(value) is Object and value has a [[SymbolData]] internal slot
3. then Return value.[[SymbolData]] //a Symbol Object
4. Throw a TypeError exception.

Example

mySymbol = Symbol( "my symbol" )

// Object() performs a type conversion when called as a function rather than as a constructor.
mySymObj = Object(mySymbol)

console.log(mySymObj.toString()) // Symbol(my symbol)