Rule 4
If an assertion does not match according to the following table, the Engine backtracks to Rule 3 and tries a higher-pecking-order item with different choices.
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^ Matches at the beginning of the string. $ Matches at the end of the string. \b Matches a word boundary (between \w and \W), when not inside []. \B Matches a non-word boundary. |
Note that Perl supports several other assertions, such as \A and \Z, which match the beginning and end of a string, respectively.
The $ assertion can match at the end of the string, or one character earlier than that, if the last character of the string is a new-line.