Question

There are two functionally equivalent ways of writing the following function in javascript, which is better or more efficient, and why?

(str) ->
  s = 0
  for i in [0...str.length]
    s += str.charCodeAt i 
  s

or

(str) ->
  s = 0
  for i in str
    s += i.charCodeAt 0 
  s

Aside: Can you suggest any other methods of doing this?

Edit: According to JSPerf, the first is faster: http://jsperf.com/coffee-for-loop-speed-test – why is this?

Answer 1

The first is both more elegant and more efficient. The second copies each character of the string to a separate string unnecessarily, before converting it to a charCode.