Price calculation based on a Index-Tree in Javascript (of Phone Numbers)

process.js

function Process(num, h) {
  var first_num = num.charAt(0)
  var following_nums = num.slice(1)
  var first_num_hash_hit = h[first_num]
  var following_nums_lookahead = following_nums.charAt(0)
 
  if(!first_num_hash_hit.hasOwnProperty(following_nums_lookahead)) 
    return null
  
  if(following_nums.length === 0) 
    return first_num_hash_hit.value
  
  if(h.hasOwnProperty(first_num)) 
    return Process(following_nums, first_num_hash_hit) || first_num_hash_hit[following_nums_lookahead].value
}