What is the shortest function for reading a cookie by name in JavaScript?

Question

What is the shortest, accurate, and cross-browser compatible method for reading a cookie in JavaScript?

Very often, while building stand-alone scri

Answer 1

Just to throw my hat in the race, here's my proposal:

function getCookie(name) {
   const cookieDict = document.cookie.split(';')
        .map((x)=>x.split('='))
        .reduce((accum,current) => { accum[current[0]]=current[1]; return accum;}, Object());
    return cookieDict[name];
}

The above code generates a dict that stores cookies as key-value pairs (i.e., cookieDict), and afterwards accesses the property name to retrieve the cookie.

This could effectively be expressed as a one-liner, but this is only for the brave:

document.cookie.split(';').map((x)=>x.split('=')).reduce((accum,current) => { accum[current[0]]=current[1]; return accum;}, {})[name]

The absolute best approach would be to generate cookieDict at page load and then throughout the page lifecycle just access individual cookies by calling cookieDict['cookiename'].