get cookie from browser javascript code example

Example 1: javascript create cookie

function setCookie(name,value,days) {
    var expires = "";
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days*24*60*60*1000));
        expires = "; expires=" + date.toUTCString();
    }
    document.cookie = name + "=" + (value || "")  + expires + "; path=/";
}
function getCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}

setCookie("user_email","[email protected]",30); //set "user_email" cookie, expires in 30 days
var userEmail=getCookie("user_email");//"[email protected]"

Example 2: document get cookie

function setCookie(cname, cvalue, exdays = 999) {
  const d = new Date();
  d.setTime(d.getTime() + exdays * 24 * 60 * 60 * 1000);
  const expires = 'expires=' + d.toUTCString();
  document.cookie = cname + '=' + cvalue + ';' + expires + ';path=/';
}

function getCookie(cname) {
  const cookies = Object.fromEntries(
    document.cookie.split(/; /).map(c => {
      const [key, v] = c.split('=', 2);
      return [key, decodeURIComponent(v)];
    }),
  );
  return cookies[cname] || '';
}

setCookie('language', 'vietnam', 365);
var userEmail = getCookie('language');

Example 3: set and get cookie in javascript

For storing array inside cookie : 
-----------------------------------
setter : var json_str = JSON.stringify(arr); cookie.set('mycookie', json_str);
getter : cookie.get('mycookie'); var arr = JSON.parse(json_str);
----------------------------------------------------------------------------
Function common for all type of variable : 
==========================================
let cookie = {
            set: function(name, value) {
                document.cookie = name+"="+value;
            },
            get: function(name) {
                let nameEQ = name + "=";
                let ca = document.cookie.split(';');
                for( let i = 0; i < ca.length; i++ ) {
                    let c = ca[i];
                    while (c.charAt(0)==' ') c = c.substring(1,c.length);
                    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
                }
                return null;
            }
        }