Symbol Type

A JavaScript Symbol is a primitive datatype just like Number, String, or Boolean.

It represents a unique "hidden" identifier that no other code can accidentally access.

For instance, if different coders want to add a person.id property to a person object belonging to a third-party code, they could mix each others values.

Using Symbol() to create a unique identifiers, solves this problem:

const person = {  
 firstName: "John",  
 lastName: "Doe",  
 age: 50,  
 eyeColor: "blue"  
};  
  
let id = Symbol('id');  
person.id = 140353;

Symbols are always unique.

If you create two symbols with the same description they will have different values.

Symbol("id") == Symbol("id") // false

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Backlinks

• Ecmascript 2015 (DevLog)