Parsing html string in php using regular expression [duplicate] - php

Question

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How do you parse and process HTML/XML in PHP?
(31 answers)
Closed 3 years ago.
I want to parse a html string using php (Simple number matching).
<i>1002</i><i>999</i><i>344</i><i>663</i>
and I want the result as an array. eg: [1002,999,344,633,...]
I tried like this :
<?php
$html="<i>1002</i><i>999</i><i>344</i><i>663</i>";
if(preg_match_all("/<i>[0-9]*<\/i>/",$html, $matches,PREG_SET_ORDER))
foreach($matches as $match) {
echo strip_tags($match[0])."<br/>";
}
?>
and I got the exact output which I want.
1002
999
344
663
But when I try the same code by making a small change in regular expression I'm getting different answer.
Like this:
<?php
$html="<i>1002</i><i>999</i><i>344</i><i>663</i>";
if(preg_match_all("/<i>.*<\/i>/",$html, $matches,PREG_SET_ORDER))
foreach($matches as $match) {
echo strip_tags($match[0])."<br/>";
}
?>
Output :
1002999344663
(The regular expression matched the entire string.)
Now I want to know why I'm getting like this?
What is the difference if use .* (zero or more) instead of [0-9]* ?

Answer 1

The .* in your regex matches any character ([0-9]* only matches numbers and </i><i> isn't a number). The regex /<i>.*<\/i>/ matches:
<i>1002</i><i>999</i><i>344</i><i>663</i>
^ from here ------------------- to here ^
Since, the whole string is inside <i></i>.
This is because * is greedy. It takes the max amount of characters it can match.
To fix your problem, you need to use .*?. This makes it takes the minimum amount of characters it can match.
The regex /<i>.*?<\/i>/ will work as you want.