Javascript bit 연산

//--- Masks ---//

var vote = 1 << 0; //1
var add = 1 << 1; //2
var remove = 1 << 2; //4
var manage = 1 << 3; //8
var comment = 1 << 4; //16
var publish = 1 << 25; //33554432

//--- Sets ---//

var user1 = vote | remove | manage; //can "vote", "remove", "manage"
var user2 = user1 | publish; //all `user1` plus "publish"
var user3 = user2 ^ manage; //all `user2` minus "manage"

//--- Matches ---//

console.log('USER 1 : ' + user1); //13

console.log(user1 & vote); //1 : TRUE
console.log(user1 & add); //0 : FALSE
console.log(user1 & remove); //4 : TRUE
console.log(user1 & manage); //8 : TRUE
console.log(user1 & comment); //0 : FALSE
console.log(user1 & publish); //0 : FALSE

console.log('USER 2 : ' + user2); //33554445

console.log(user2 & vote); //1 : TRUE
console.log(user2 & add); //0 : FALSE
console.log(user2 & remove); //4 : TRUE
console.log(user2 & manage); //8 : TRUE
console.log(user2 & comment); //0 : FALSE
console.log(user2 & publish); //33554432 : TRUE

console.log('USER 3 : ' + user3); //33554437

console.log(user3 & vote); //1 : TRUE
console.log(user3 & add); //0 : FALSE
console.log(user3 & remove); //4 : TRUE
console.log(user3 & manage); //0 : FALSE
console.log(user3 & comment); //0 : FALSE
console.log(user3 & publish); //33554432 : TRUE