Bit Flags: Many Options in One Number

Bit flags store several yes/no options in one integer: each option gets a power of two, and you combine them with OR. It's how Unix permissions, many APIs and game engines store settings compactly.

A user with READ, WRITE and SHARE

const perms = READ | WRITE | SHARE;   // 11, binary 01011
const canShare = (perms & SHARE) !== 0;  // true
const canDelete = (perms & DELETE) !== 0; // false
const withDelete = perms | DELETE;       // 15

• In a database, a flags column is compact but hard to query and read; separate booleans or a join table are often clearer.
• JavaScript bitwise operators work on 32 bits; use BigInt for more than 31 flags.