res.cookie not working with array javascript code example

Example 1: set and get array inside cookie in javascript

JSON encode it, effectively producing a string like "{name:'myname',age:'myage'}"
which you put in a cookie, retrieve when needed and decode back into a 
JavaScript array/object.

Example - store array in a cookie:
----------------------------------
var arr = ['foo', 'bar', 'baz'];
var json_str = JSON.stringify(arr);
createCookie('mycookie', json_str);

Later on, to retrieve the cookie's contents as an array:
--------------------------------------------------------
var json_str = getCookie('mycookie');
var arr = JSON.parse(json_str);

Example 2: set and get array inside cookie in javascript

cookie = {
    set: function(name, value) {
        document.cookie = name+"="+value;
    },
    get: function(name) {
        cookies = document.cookie;
        r = cookies.split(';').reduce(function(acc, item){
            let c = item.split('='); //'nome=Marcelo' transform in Array[0] = 'nome', Array[1] = 'Marcelo'
            c[0] = c[0].replace(' ', ''); //remove white space from key cookie
            acc[c[0]] = c[1]; //acc == accumulator, he accomulates all data, on ends, return to r variable
            return acc; //here do not return to r variable, here return to accumulator
        },[]);
    }
};
cookie.set('nome', 'Marcelo');
cookie.get('nome');