get-property.js

function is_object(a) {
  return a && (typeof a === 'object');
}

function step(last, current) {
  if(is_object(last)) {
    return last[current];
  }
}

function get_property(obj, path) {
  return path.split('.').reduce(step, obj);
}

/*
 * > get_property({'foo':{'bar': 1}}, 'foo.bar')
 * 1
 * > get_property({'foo':{'bar': 1}}, 'foo')
 * { bar: 1 }
 * > get_property({'foo':{'bar': 1}}, 'foo.bar.hello')
 * undefined
 */