Ruby: Create new string at every replacement

Question

How to create a list of strings with only one replace of matched pattern in ruby.

For example:

The given string is "aaaazzzazazaaaazzzazaaaazz". I need to replace "aaaa" with "A". So I would get a such list:

• "Azzzazazaaaazzzazaaaazz"
• "aaaazzzazazAzzzazaaaazz"

• "aaaazzzazazaaaazzzazAzz"

   s = gets.strip
   stor="aaaa"
   sforr="A"
   a = s.split(stor)
   (a.length-1).times { |x| puts a[0..x].join(stor)+sforr+
                                 a[x+1..a.count-1].join(stor) }
  

Answer 1

You could use String#scan with a block:

str = "aaaazzzazazaaaazzzazaaaazz"
str.scan(/aaaa/) { |m| puts "#{$`}A#{$'}" }

Output:

Azzzazazaaaazzzazaaaazz
aaaazzzazazAzzzazaaaazz
aaaazzzazazaaaazzzazAzz

$` and $' are global variables, referencing the strings to the left and to the right of the last match.