# Reference

|    Name    |                   Description                  |  Example  |
| :--------: | :--------------------------------------------: | :-------: |
|      g     |                 global boundary                | /\[a-z]/g |
|   globle   |                test g is or not                |           |
|      i     |                case-insensitive                | /\[a-z]/i |
| ignoreCase |                test i is or not                |           |
|      .     |          any character except newline          |    /\*/   |
|     \w     |              word equal to \[A-z]              |    /\w/   |
|     \W     |        not word equal to  \[]\*%$@# etc        |    /\W/   |
|     \d     |              digit equal to \[0-9]             |    /\d/   |
|     \D     | not digit  equal to anything except for \[0-9] |    /\D/   |
|     \s     |                   whitespace                   |    /\s/   |
|     \S     |                 not whitespace                 |    /\S/   |
|   \[ABC]   |    select A, B or C; if it's \[D], select D    |  /\[ABC]/ |
|   \[^ABC]  |       not select A, B or C; select others      | /\[^ABC]/ |
|     \b     |         select a word the last alphabet        |   /ed\b/  |
|     \D     |       select a word not the last alphabet      |   /ed\D/  |
|      ^     |                      start                     |   /^ed/   |
|      $     |                       end                      |   /ed$/   |