Parse document.cookie into object

parsecookie.js

document.cookie.split(';').map(function(c) {
  return c.trim().split('=').map(decodeURIComponent);
}).reduce(function(a, b) {
  try {
    a[b[0]] = JSON.parse(b[1]);
  } catch (e) {
    a[b[0]] = b[1];
  }
  return a;
}, {});

Rewrite to work on older browsers / js versions:

Object.fromEntries(document.cookie.split(/; */).map(function(c) {
    var index = c.indexOf("=");     // Find the index of the first equal sign
    var key   = c.slice(0, index);  // Everything upto the index is the key
    var value = c.slice(index + 1); // Everything after the index is the value

    // Return the key and value
    return [ decodeURIComponent(key), decodeURIComponent(value) ];
}));

https://stackoverflow.com/a/64472572/8784402

Object.fromEntries(document.cookie.split('; ').map(v=>v.split(/=(.*)/s).map(decodeURIComponent)))

+1, thanks for the helpful code!