Search⌘ K
AI Features
Home
Courses
Rediscovering JavaScript: ES6, ES7 & ES8

Global Registry With Symbol

Explore the unique nature of JavaScript Symbols, how Symbol.for creates or retrieves Symbols from a global registry, and using Symbol.keyFor to find associated keys. Understand these concepts to manage special identifiers and improve your JavaScript code design.

We'll cover the following...

Uniqueness of Symbols

When we create a Symbol using the Symbol() function, the argument passed to it has no significance, and each call to Symbol() creates a unique Symbol.

Proof by example

Let’s quickly verify this behavior with an example.

Javascript (babel-node)
'use strict';
//START:CODE
const name = 'Tom';
const tom = Symbol(name);
const jerry = Symbol('Jerry');
const anotherTom = Symbol(name);
console.log(tom);
console.log(typeof(tom));
console.log(tom === jerry);
console.log(tom === anotherTom);
//END:CODE

Explanation

  • We created three Symbols. Two of them were created using the same argument name.
  • However, since the arguments passed to the function have no significance and the Symbol
...