12. Metacharacters - Alternation and Grouping

• You can provide alternation in regular expressions with the pipe character:

    |
          

• Remember our regex to match "grey" or "gray"? We could also have done the regex this way:

    grey|gray
          

• We can also use round brackets to provide logical grouping of characters to limit the scope of alternation. Thus, we could also write:

    gr(e|a)y
          

  to get another regex to search for "grey" or "gray"!
• Yes, I'm lying about the brackets a bit. We'll get back to them later.