Immutable-js: Best way to accomplish sum()?

[Anahkiasen]

I'm transitioning my codebase from custom objects + Lodash and so far Immutable has replaced both perfectly. But there's ont thing I can't seem to do easily which is to get the sum of a List/Map. Currently doing this:

let total = 0;
entries.forEach(entry => total += entry.get('price'));

Is there anything similar to Lodash's sum like entries.sum('price') or entries.sum(entry => entry.get('price')) or something that I missed in the documentation?

[edvinerikson]

I couldn't find any methods like sum but I guess the closest way to accomplish something like sum is to use the reduce method.

var entries = Immutable.fromJS([
    {price: 1},
    {price: 2},
    {price: 3},
]);

var sum = entries.map(entry => entry.get('price')).reduce((prev, current) => prev + current);
console.log(sum); // 6

[kentor]

reduce is pretty much the standard way to do these aggregation operations in functional programming

[leebyron]

Closing out. reduce is the way to go!