Ruby: Check if string contains substring
August 7, 2022 ‐ 1 min read
To check whether a Ruby string contains a given substring the
include? string method seems most convenient. You can pass it the substring as an argument and it returns either
if 'rubylation'.include?('ruby') puts 'We found a match!' end #=> We found a match!
include? method looks for an exact match of the substring in the string. Therefore it is case sensitive for example.
If you are looking for a more advanced way of looking for a substring in a string you can look at regular expressions.
This returns the index of the match if found, if the string doesn't contain a match for the regular expression
nil is returned.
'rubylation' =~ /Ruby/ #=> nil
'rubylation' =~ /Ruby/i #=> 0