<ul><li>JavaScript introduced the Symbol type to create hidden property keys.</li><li>Symbols do not show up when objects are looped over or printed out.</li><li>To create a Symbol, the Symbol() function is used.</li><li>Symbols are unique with the same description strings yielding different values.</li><li>Symbols behave as object keys by being matched by identity.</li><li>Symbol properties are stored separately and do not mix with string keys.</li><li>Symbol keys are treated differently in property lookups and iterations.</li><li>Symbols are flagged as non-enumerable and skipped in common lookup methods.</li><li>Symbol properties can be accessed using Object.getOwnPropertySymbols().</li><li>Symbols are ideal for hiding data within objects and maintaining privacy.</li></ul>

Inside the Mechanics of JavaScript Symbol Properties

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