Explode a string to an array

Question

Probably easy to do but I can't seem to generate the correct regex.

Say I have this string

$string = '<h2>Header 1</h2><p>ahs da sdka dshk asd haks</p><img src="http://dummyimage.com/100x100/" width="100" height="100" alt="Alt" /><h2>Header 2</h2><p>asdkhas daksdha kd ahs</p><em>Lame</em><p>trhkbasd akhsd ka dkhas</p><h2>Header 3</h2><p>ajdas ahkds hakd</p>';

And I need it like this

$array[0] = '<h2>Header 1</h2><p>ahs da sdka dshk asd haks</p><img src="http://dummyimage.com/100x100/" width="100" height="100" alt="Alt" />';
$array[1] = '<h2>Header 2</h2><p>asdkhas daksdha kd ahs</p><em>Lame</em><p>trhkbasd akhsd ka dkhas</p>';
$array[2] = '<h2>Header 3</h2><p>ajdas ahkds hakd</p>';

...and so on if my string contains more of those H2 blocks.

So, the split-point is at H2 and it needs to keep the HTML-tags. Any pointers?

Answer 1

$result = split('(?=<h2>)', $string);

or

$result = preg_split('/(?=<h2>)/', $string);

Answer 2

$string = '<h2>Header 1</h2><p>ahs da sdka dshk asd haks</p><img src="http://dummyimage.com/100x100/" width="100" height="100" alt="Alt" /><h2>Header 2</h2><p>asdkhas daksdha kd ahs</p><em>Lame</em><p>trhkbasd akhsd ka dkhas</p><h2>Header 3</h2><p>ajdas ahkds hakd</p>';

$matches    = split('<h2>', $string);

print_r($matches);

This is deprecated as of PHP 5.3.0 though.

Answer 3

Use preg_split() with a positive lookahead for the opening tag:

print_r(preg_split('/(?=<h2>)/', $string, -1, PREG_SPLIT_NO_EMPTY));

The positive lookahead simply tells the regex parser to split text surrounding <h2>, but not eliminate the tag. If you split by /<h2>/, the tag disappears, just like if you split with explode().