RegExpressions Help

chrisdarby

I am trying to get to grips with regular expressions having never used them before. What I am trying to do is process a string such as.

This is a #test# string with some #content# in it that I want to #process# today

I would like to have an expression to go through the string and generate an array that would contain

#test#
#content#
#process#

Anyone have any ideas what would be the best way to do that ?

Drakla

Well the code to do that would be something like

<?php
$str = "This is a #test# string with some #content# in it that I want to #process# today";

$pat = '!#.*#!U';

$found = preg_match_all($pat, $str, $matches);


echo '<pre>'; print_r($matches); echo '</pre>';
?>

In the pattern a match is made of any characters between hashes, and the U modifier to the pattern makes it 'ungreedy' or 'lazy'. A great tutorial on regex is here http://www.regular-expressions.info/tutorial.html
I did loads and that was by far the best.

You could add a capturing pattern to the regex pattern so that just the text would be captured without the hashes, but I'll leave that to you, as the tutorial should make it easy to do.

FatalError

I'm going to slightly change the example above by making it easier to use the elements of the new array easier.

<?php
$str = "This is a #test# string with some #content# in it that I want to #process# today";

$pat = '!#(.*)#!u'; // This is the pattern you're looking for, in this case two #'s

preg_match_all($pat, $str, $matches);

$match_count = count($matches[1]);
$array = array();

for ($a=0; $a < $match_count; $a++)
{
$array[] = $matches[1][$a];
}

echo '<pre>';
print_r($array); // This just prints the contents of the array
echo '</pre>';
?>

Basically what I did here is I added the array $array, where each element is another string matched by the preg_match function. In this example, $array[0] would be "test", $array[1] would be "content", etc etc.