Handling cookies with Javascript

cookies.js

/**
 * Creates or Updates a cookie
 */
function setCookie(name, value, expiry /* in days */ ) {
    var d = new Date()
    d.setTime(d.getTime() + (expiry * 24 * 60 * 60 * 1000))
    var expires = 'expires=' + d.toUTCString()
    document.cookie = name + '=' + value + ';' + expires + ';path=/'
}

/**
 * Returns a cookie
 */
function getCookie(name) {
    name = name + '='
    var decodedCookie = decodeURIComponent(document.cookie)
    var cookies = decodedCookie.split(';')

    for (var i = 0; i < cookies.length; i++) {
        var cookie = cookies[i]

        while (cookie.charAt(0) == ' ') {
            cookie = cookie.substring(1)
        }

        if (cookie.indexOf(name) == 0) {
            return cookie.substring(name.length, cookie.length)
        }
    }

    return null
}

/**
 * Returns all cookies
 */
function getCookies() {
    var allCookies = []
    var decodedCookie = decodeURIComponent(document.cookie)
    var cookies = decodedCookie.split(';')

    for (var i = 0; i < cookies.length; i++) {
        var cookie = cookies[i]

        while (cookie.charAt(0) == ' ') {
            cookie = cookie.substring(1)
        }

        if (cookie.length) {
            cookie = cookie.split('=')
            allCookies.push({
                name: cookie[0],
                value: cookie[1]
            })
        }
    }

    return allCookies.length ? allCookies : null
}

/* Usage */
var cookieName = 'jscookie'

// Create a cookie
setCookie(cookieName, 'JS Cookies!!!', 1)

// Get cookie value
var cookieValue = getCookie(cookieName)

// Get all cookies
var allCookies = getCookies()

// Check if a cookie exists
if (getCookie(cookieName) !== null) {
    console.log(cookieName + ' exists.')
}

// Check if a cookie does not exist
if (getCookie(cookieName) === null) {
    console.log(cookieName + ' does not exist.')
}

// Unset a cookie
setCookie(cookieName, 1, -1)