- explode: documentation ( source)
- preg_replace: documentation ( source)
<?php
$sometext = "Some text **that is bold!** and some other text**";
$string = explode('**', $sometext);
$newstr = '';
$size = count($string);
for ($i = 0; $i < $size; ++$i) {
if (($i % 2 == 0 || $i == 0 )&& $i != $size-1 )
$newstr .= $string[$i]."<b>";
else if($i % 2 != 0 && $i != $size && $i != $size-1 )
$newstr .= $string[$i]."</b>" ;
else if($i == $size-1)
$newstr .= $string[$i];
}
$s = preg_replace(
'/\*\*(.+?)\*\*/isU',
'<b>$1</b>',
$sometext);
echo $s;
echo "\n".$newstr;