getNested.js

function getNested(obj, deepKey, delimiter = '.') {
    let args = deepKey.split(delimiter);

    for (let i = 0; i < args.length; i++) {
        if (!obj || !obj.hasOwnProperty(args[i])) {
            return undefined;
        }
        obj = obj[args[i]];
    }
    return obj;
}