get object property by path

path.js

Object.getValue = function(obj, path) {
    if (typeof obj === 'undefined' || obj === null) return;
    path = path.split(/[\.\[\]\"\']{1,2}/);
    for (let i = 0, l = path.length; i < l; i += 1) {
        if (path[i] !== '') {
            obj = obj[path[i]];
            if (typeof obj === 'undefined' || obj === null)  {
                return;
            }
         }
    }
    return obj;
}

var user = {name: 'John', address: [{street: 'River Ave'}]};
Object.getValue(user, 'address[0].street'); // River Ave
Object.getValue(user, 'occupation[9].company'); // null