From: yermej <yermej@...>
Date: 2007-12-19T00:05:01+09:00
Subject: Re: Convert a char into numbre

On Dec 18, 8:35 am, Roberto Decurnex Gorosito
<decurnex.robe...@gmail.com> wrote:
> I am have an String object like "12345678", and an Array object like
> [ 8,7,6,5,4,3,2,1].
> The main idea is:
>
> myStr = '12345678'
> myArray = [8,7,6,5,4,3,2,1]
> total = 0
>
> for i in 0..7
>  total+= myStr[ i ].to_i  * myArray[ i ]
> end
>
> The awaited result is 120 but coz myStr[ i ] returns the ascii fixnum
> i can' t get it

Fixnum#chr will give you the String back and then you can use
String#to_i:

total = 0
myArray.each_with_index do |x, i|
  total += x * myStr[i].chr.to_i
end
total
=> 120

Alternately, you could just subtract 48 from myStr[i] if you'll always
be using ASCII, but I don't think that's a good way to do things.

As a one-liner:
myStr.split(//).zip(myArray).inject(0) {|acc, arr| acc + arr[0].to_i *
arr[1]}
=> 120