Question

I have an object that looks like this one:

object =
  title : 'an object'
  properties :
    attribute1 :
      random_number: 2
      attribute_values:
        a: 10
        b: 'irrelevant'
    attribute2 :
      random_number: 4
      attribute_values:
        a: 15
        b: 'irrelevant'
   some_random_stuff: 'random stuff'

I want to extract the sum of the ‘a’ values on attribute1 and attribute2.
What would be the best way to do this in Coffeescript?

(I have already found one way to do it but that just looks like Java-translated-to-coffee and I was hoping for a more elegant solution.)

Answer 1

Here is what I came up with (edited to be more generic based on comment):

sum_attributes = (x) =>
  sum = 0
  for name, value of object.properties 
    sum += value.attribute_values[x]
  sum

alert sum_attributes('a') # 25
alert sum_attributes('b') # 0irrelevantirrelevant

So, that does what you want… but it probably doesn’t do exactly what you want with strings.
You might want to pass in the accumulator seed, like sum_attributes 0, 'a' and sum_attributes '', 'b'