The following list summarizes the expressions discussed above:
- c
Literal character
- .
Any character except newline
- ^
Beginning of line
- $
End of line (null string before newline)
- [xyz]
Character class (any one of these characters)
- [^xyz]
Negated character class (all but these characters)
- *
Closure (zero or more instances of previous pattern)
- \c
Escaped literal character (for example, \^, \[, \*)
Any special meaning of metacharacters in a regular expression is lost when
1) escaped, 2) inside [...], or 3) for the following characters:
- ^
When not at the beginning of an expression
- $
When not at end of an expression
- *
When beginning an expression
A character class consists of zero or more of the following
elements, surrounded by ``[`` and ``]":
- c
Literal characters, including [
- a-b
Range of characters (digits, lowercase or uppercase)
- ^
Negated character class if at beginning
- \c
Escaped character (for example, \^ \- \\ \])
Special meaning of characters in a character class is lost when
1) escaped or 2) for the following characters:
- ^
When not at beginning of a character class
- -
When at beginning or end of a character class
An escape sequence consists of the character \ followed by a single character:
System Debug expects regular expressions to be enclosed in back quotes "`".
System Debug commands support MPE XL style wildcard patterns. These
are converted into regular expressions for evaluation.
- @
Matches any character (same as `.*`)
- ?
Matches any alphabetic character (same as `[a-zA-Z]`)
- #
Matches a numeric character (same as `[0-9]`)