Loop through array of objects and return sum of each total values by object element id

Question

I\'m calculating taxes for a very complicate invoicing approach. I can\'t explain the whole process but if you have questions I will answer as best as I can

Answer 1

My solution using typed arrays:

var sum_arr = new Float32Array(arr.length); for (var i = 0; i < arr.length; i++){ var tax_id = arr[i].tax_id; sum_arr[tax_id] += parseFloat(arr[i].tax_value); }

jsfidle: http://jsfiddle.net/LJ7Nd/

The idea: assume you have n tax_ids. Create an array of length n called sum_arr. Pull the tax_id at each iteration and increment that particular slot in the array by the corresponding tax_value. Then when you want the sum of all tax_values of tax_id = 1 you simply index sum_arr[1].