JavaScript Symbols

What are Symbols?

Symbols create unique identifiers. Each symbol is unique.

const sym1 = Symbol('id');
const sym2 = Symbol('id');

sym1 === sym2; // false (always unique!)

Using Symbols as Keys

const id = Symbol('id');
const user = {
  name: 'John',
  [id]: 123
};

Key Takeaway

Symbols create unique values. Use as object keys for privacy. Each symbol is always unique.