Regular expressions - search and replace question 2

[Dweezel]

I need to parse a string and replace newline characters (either '\n' or'\r') with <p> tags.

Is preg_replace() the best function to use for this?

If there are two or more newline tags together, they must only produce one <p> tag. So if the string contained '\n\n\n' or '\r\r\r' or '\n\r', I'd need to replace it with a single <p>.

Could anyone help me out with the syntax please?

 

[sleipnir214]

That regular expression is actually easier than you might think. Its English translation would be, "Any number of newlines or carriage returns in a row".

This script:

<?php

$a = array ("\r", "\n", "\r\n", "\r\r", "\n\n", "\r\n\r\n", "\r\r\n", "a\ra", "a\r\na", "\ra\r", "\r\na\r\n");

$a = preg_replace ("/([\r\n])+/", '<p>', $a);

print_r ($a);
?>

outputs:

[tt]Array
(
[0] => <p>
[1] => <p>
[2] => <p>
[3] => <p>
[4] => <p>
[5] => <p>
[6] => <p>
[7] => a<p>a
[8] => a<p>a
[9] => <p>a<p>
[10] => <p>a<p>
)[/tt]


Want the best answers? Ask the best questions!

TANSTAAFL!!

 

[Rekcor]

I think preg_replace() is fine. Here is a great reference (and website) of regular expressions:

http://www.regular-expressions.info/reference.html

A quick solution (dont know if it works):

$pattern = "/\n{1,}|\r{1,}(\r\n){1,}/";
$replacement = "<p>";
echo preg_replace($pattern, $replacement, $yourStringHere);

 

[Dweezel]

Thanks a lot Sleipnir, that's exactly what I needed.

And thanks for the link Rekcor. I'll have a good look through that at the weekend.

Cheers.