Return index of all occurrences of a character in a string in ruby

Question

I am trying to return the index's to all occurrences of a specific character in a string using Ruby. A example string is "a#asg#sdfg#d##" and the expected return is [1,5,10,12,13] when searching for # characters. The following code does the job but there must be a simpler way of doing this?

def occurances (line)    index = 0   all_index = []    line.each_byte do |x|     if x == '#'[0] then       all_index << index     end     index += 1   end    all_index end 

Answer 1

s = "a#asg#sdfg#d##" a = (0 ... s.length).find_all { |i| s[i,1] == '#' } 

Answer 2

require 'enumerator' # Needed in 1.8.6 only "1#3#a#".enum_for(:scan,/#/).map { Regexp.last_match.begin(0) } #=> [1, 3, 5] 

ETA: This works by creating an Enumerator that uses scan(/#/) as its each method.

scan yields each occurence of the specified pattern (in this case /#/) and inside the block you can call Regexp.last_match to access the MatchData object for the match.

MatchData#begin(0) returns the index where the match begins and since we used map on the enumerator, we get an array of those indices back.