preg_replace problem- Need help in highlight keywords

[bnownlater]

I am trying to highlight just the begining of words in a string that start with my keyword. So if a user submitted "hat" the word "hatter" would be highlight as such, but the word "that" would not. Any suggestions.

Here is my code that currently highlights every instance of the keyword:

for($i=0;$i<count($keyword2);$i++){

		If ($i==0){
	 		$titlestr2=preg_replace("'($keyword2[$i])'si","[:;]\\1[;:]",$titlestr);
        }else{
		  	$titlestr2=preg_replace("'($keyword2[$i])'si","[:;]\\1[;:]",$titlestr2);
        }
    }

	for($i=0;$i<count($keyword2);$i++){

	 		$titlestr3 = str_replace("[:;]","<span class=\"highlight2\">",$titlestr2);
	 	  	$titlestr3=str_replace("[;:]","</span>",$titlestr3);
   }
    echo $titlestr3;

[[deleted]]

Here's a little something that may work for you...

<?
$test[] = "The hat that ran over the cat.";
$test[] = "Hatter left his ball that he likes.";
$test[] = "Hats are weird";
$test[] = "That dog ate my shoe";

$word = 'hat';
$results = array ();

$results = preg_replace("/\b($word)/i", "<font color=\"red\">$1</font>", $test);

foreach ($results as $result) {
    echo "$result<BR>\n";
}
?>

[RoadKingHD]

In the following:

$results = preg_replace("/b($word)/i", "<font color=\"red\">$1</font>", $test);

The word boundary (anchor) should be \b

$results = preg_replace("/\\\\b($word)/i", "<font color=\"red\">$1</font>", $test);

Works perfect, thanks!

[[deleted]]

Yes it should be...sorry the forum ate my backslash...

[bnownlater]

That was what i was lookign for. Thanks.