How to replace the last occurrence of a substring in ruby?

Question

I want to replace the last occurrence of a substring in Ruby. What\'s the easiest way? For example, in abc123abc123, I want to replace the last abc

Answer 1

simple and efficient:

s = "abc123abc123abc"
p = "123"
s.slice!(s.rindex(p), p.size)
s == "abc123abcabc"