Question

I am pretty green when it comes to php, so here’s a basic question for which I have not found an answer yet.

I extract repetitive information from a page by doing regex matching as follows. The regex has two capturing groups (…), hence the $matches array has index ranging from 0 (full regex value) to 2 ( 1 and 2 are the capturing group values).

<?php
    $page = file_get_contents(url);
    preg_match_all(regex-with-two-capturing-groups, $page, $matches);
    $m1 = $matches[1];
    $m2 = $matches[2];
    for ($i=0; $i < sizeof($m1); $i++) {
        echo ("<tr><td>$m1[$i]</td><td>$m2[$i]</td></tr>");
    }
?>

This works fine, but at first I tried a shorter version:

<?php
    $page = file_get_contents(url);
    preg_match_all(regex-with-two-capturing-groups, $page, $matches);
    for ($i=0; $i < sizeof($matches[0]); $i++) {
        echo ("<tr><td>$matches[1][$i]</td><td>$matches[2][$i]</td></tr>");
    }
?>

but this resulted in

<tr><td>Array[0]</td><td>Array[0]</td></tr>
<tr><td>Array[1]</td><td>Array[1]</td></tr>
<tr><td>Array[2]</td><td>Array[2]</td></tr>
<tr><td>Array[3]</td><td>Array[3]</td></tr>
<tr><td>Array[4]</td><td>Array[4]</td></tr>
...

Why is this?
And is there a way to do two-dimensional indexing in one expression, not having to define intermediate arrays m1 and m2?

Answer 1

Use this code:

<?php
    $page = file_get_contents(url);
    preg_match_all(regex-with-two-capturing-groups, $page, $matches);
    for ($i=0; $i < sizeof($matches[0]); $i++) {
        echo ("<tr><td>".$matches[1][$i]."</td><td>".$matches[2][$i]."</td></tr>");
    }
?>

PHP Documentation : language.types.string.parsing

Look also here : PHP: concatenation of multidimensional array elements