Access a nested object property using a string with Lodash / Underscore (or another implementation of the reduce() function)

get_nested_obj_property.js

function getObjProperty(containerObj, str, defaultValueArg) {
	var defaultValue = typeof defaultValueArg !== 'undefined' ? defaultValueArg : null;

	try {
		return _(str.split('.')).reduce(function(obj, key) {
			return obj[key];
		}, containerObj);
	} catch (e) {
		return defaultValue;
	}
}

// Example:

var elem = {
	product: {
		brand: { id: "123", name: "Product Brand" }
	}
};

getObjProperty(elem, "product.brand.name");
// returns: "Product Brand"

getObjProperty(elem, "product.manufacturer.name", "Default manufacturer");
// not found, returns: "Default manufacturer"