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Simple Pattern Matching

There is a class for regular expressions (Regexp) and a “matching” operator (=~). To express a regex literal, we usually surround it with forward slashes. The simplest regular expressions are treated just like substrings.

re = /tuv/
re.type         #-> Regexp
re =~ "rstuvwx" #-> 2
re =~ "Tavern"  #-> nil

Note

The forward slashes are traditional. Just as with string literals, you can specify some other delimiter; start with %r to make it clear that you want a regular expression. %r[xyz] is the same as /xyz/.

"tuv" is a substring of "rstuvwx" and not "Tavern". Why do we get 2 and nil instead of true and false? Remember, anything other than nil or false is considered true, so we can use these to make yes/no decisions as if they ...