Introduction to Regex

    * 0 or more matches
    + 1 or more matches
    ? 0 or 1 match
    ^ matches the start of the string or line
    $ matches the end of the string or line
    \ signifies an escape sequence
    . matches any single character except newline
    ( ) capturing group. Save to reuse later
    | used as a logic OR inside a capturing group
    [abc] character set. Matches one of the things in the brackets
    [^abc] Negated character set. Matches anything except...
    [a-zA-Z] all upper and lowercase letters. You can specify any range.
    {1} exact number of matches. Comes after a set or group.
    {1,5} inclusive range for number of matches
    {1,} minimum number of matches
    {,5} maximum number of matches
    \s any whitespace character
    \S any NON whitespace character
    \d any digit. Same as [0-9]
    \D any NON digit
    \w any word character. Same as [a-zA-Z0-9_]
    \W any NON word character. Same as [^a-za-z0-9_]
    \b word boundary
    \B NON word boundary
    [\b] - escape sequence for a backspace character
    \u0404 - 4 digit unicode hex value for a character