| (?-i)
| set case sensitivity
|
| (?i)
| turn OFF case sensitivity after (?-i)
|
| ^
| start of line or negates character class
|
| $
| end of line
|
| .
| match any character (wildcard)
|
| ?
| 0 or 1 quantifier
|
| *
| 0 or more quantifier
|
| +
| 1 or more quantifier
|
| \s
| any whitespace character
|
| \S
| character is NOT a whitespace character
|
| \w
| any "word" character
|
| \W
| any "NON-word" character
|
| \b
| word boundary
|
| \B
| NOT a word boundary
|
| \d
| a decimal digit
|
| \D
| character is NOT a decimal digit
|
| \
| general escape character (metacharacters)
|
| \\
| backslash character
|
| {8}
| Repetition Example: match exactly 8
|
| {3,}
| Repetition Example: three or more
|
| {2,4}
| Repetition Matches 2, 3, or 4 repetitions
|
{,3}
| NO (a number MUST come before the comma)
|
| ( )
| start and end of subpattern |
