JavaScript Symbols_basics Guide
Symbols are unique primitives used as object keys to prevent name collisions and enable metaprogramming. The guide walks through Symbol Fundamentals. `Symbol("desc")` — unique. `Symbol.for("global")` — shared registry. `Symbol.keyFor(sym)` — get registry key. As property keys: `obj[Symbol("id")] = value`. Well-known: Symbol.iterator, Symbol.asyncIterator, Symbol.toStringTag, Symbol.toPrimitive, Symbol.match, Symbol.replace, Symbol.hasInstance. The guide is organized into 1 sections that build on each other, each pairing a prose explanation with runnable code. Related guides: Arrays, Strings, Numbers, Math, Date. This is one of 145 JavaScript guides on JS Reference — see the full list on the guides page. Practice what you learn in the JavaScript playground, and look up any unfamiliar term in the JavaScript glossary.