php - RegEx with optional part inside

Solution:

How about this:

\[element title=(.*)picture=(\d+)\](.*?)(\[caption\](.*)\[/caption\])?\[/element\]
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It will match both:

[element title=element title picture=32]Lorem ipsum dolor[caption]Photo by John Doe[/caption][/element]

[element title=element title picture=32]Lorem ipsum dolor[/element]
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Example

in PHP, you can use it this way:

$regex = '#\[element title=(.*)picture=(\d+)\](.*?)(\[caption\](.*)\[/caption\])?\[/element\]#i';
$text = '[element title=element title picture=32]Lorem ipsum dolor[caption]Photo by John Doe[/caption][/element]';    

preg_match ( $regex, $text, $match );

print_r( $match );
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The array$match will have several elements. Those are the strings that are surrounded by round-brackets( and) in the regular expression. One of them is the caption text.

Program execution and output can be seen here .

Solution:

\[element title=(.*) picture=[0-9]+\](.*)(\[caption\](.)*\[\caption\])?\[/element\]
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