What is the difference between gsub and sub methods for Ruby Strings

Question

I have been perusing the documentation for String today, and I saw the :sub method, which I\'d never noticed before. I\'ve been using :gsub

Answer 1

value = "abc abc"
puts value                                # abc abc
# Sub replaces just the first instance.
value = value.sub("abc", "---")
puts value                                # --- abc
# Gsub replaces all instances.
value = value.gsub("abc", "---")
puts value                                # --- ---