A regular expression is a structured string that is used to match other strings. You can use regular expressions for data invalidation and for filtering the messages that display in the message center.
| Regular expression | Description |
|---|---|
| . | Finds any one character. |
| .* | Finds any one character zero or more times. |
| A.* | Finds all strings that start with "A". |
| .*A | Finds all strings that end with "A". |
| A? | Finds "A", zero or one time. |
| A* | Finds "A", zero or many times. |
| A+ | Finds "A", one time or many times. |
| A?B*C+ | Finds any one character, followed by zero or one A, followed by zero or many Bs, followed by one or many Cs |
| [ABC].* | Finds strings that start with the letters "A", or "B", or "C". |
| .*ABC.* | Finds strings with the string "ABC" somewhere in the string. |
| (ABC|DEF).* | Finds strings that start with the string "ABC" or "DEF". |