Delimiter must not be alphanumeric or backslash¶
Description¶
The first character of a regex is the delimiter, that delimits the regex. There is a first and a last delimiter.
In the case of this error, the first regex character is of invalid type. It cannot be alphanumeric (a-z, A-Z and digits), nore the backslash \
.
Note that if the first characters are white spaces, such as space, tabulation, new line, they are ignored as potential delimiter.
Later, the NUL character (chr(0)
) was added to the list of the forbidden characters.
Example¶
<?php
preg_match('a[bc]a', 'abc');
?>
Solutions¶
Use a non-alphanumeric character, like
/
,#
.
See Also¶
In more recent PHP versions, this error message is now Delimiter must not be alphanumeric, backslash, or NUL.