The reduce function in ImmutableJS allows you to transform and create new data from an existing data structure. In this example, we will do some math and calculate a sum based on data in an ImmutableJS Map.
In this example, I'm returning an assignment with +=
:
const subtotal = cart.get('items').reduce((t, i) => t += i.get('price'), 0)
This code works, but it's not necessary to do the assignment, since the sum is what I actually want:
const subtotal = cart.get('items').reduce((t, i) => t + i.get('price'), 0)