<?php
 
$rows[0][0] = "The world is ending";
$rows[0][1] = "What should we do";
$rows[0][2] = "You are the best";
$rows[0][3] = "Turn left at the next exit";
 
$rows[1][0] = "You gave me life";
$rows[1][1] = "Will you be my friend";
$rows[1][2] = "I like you more everyday";
$rows[1][3] = "Is that a wig on your head";
 
$q = "a b c d";
$q_array = explode(" ", $q);
$q_array = array_unique($q_array);
$q_array = array_values($q_array);
 
$num_q = count($q_array);
 
foreach ($q_array as $key) $q_array1[] = "!($key)!i";
 
foreach($rows as $key){
  $row .= "<tr>";
  foreach($key as $str){
  $str = preg_replace($q_array1, "<b>$1</b>", $str);
  $row .= "<td>$str</td>";}
$row .= "</tr>";
}
 
echo "<table border=\"1\">$row</table>";
 
print_r($q_array1);
 
?>

<?php
 
$row = "You are the best";
 
$q = "a b";
 
$q_array = explode(" ", $q);
 
foreach ($q_array as $key) $q_array1[] = "!($key)!i";
 
$str = preg_replace($q_array1, "<b>$1</b>", $row);
 
echo $str; 
 
?>

<?php
function makeBold($var){
   return (ereg_replace("[a|b]+[a-z]+[a-z]","<b>\\0</b>",$var));
}
$row = "You are the best";
echo makeBold($row);
?>

<?php
$group =array("A","a","B","b");
$row = "You are the best At BaseBall";
$all = implode("|",$group); // convert the array into a pipe delimited string
echo (ereg_replace($all,"<b>\\0</b>",$row));
?>

foreach($row as $str) echo(eregi_replace($q,"<b>\\0</b>",$str));

$replace = array('a', 'b');
$replacements = array('<b>a</b>', '<b>b</b>');
 
$subject = "You are the best At BaseBall";
 
$subject= str_ireplace($replace, $replacements, $subject);
 
echo $subject;

$replace = array('a', 'b');
 
$subject = "You are the best At BaseBall";
 
foreach($replace as $x) {
$subject  = str_ireplace($x, '<b>'.$x.'</b>', $subject);
}
 
echo $subject;