Using preg_match to find a group in a string?

I'm trying to find special characters with characters like <开发者_JAVA百科?, <?php, or ?> in a string. The code below works to find "php" in the string anywhere no matter if it's PHP, php, or phpaPHPa.

<?php
$searchfor = "php";
$string = "PHP is the web scripting language of choice.";
if (preg_match("/".$searchfor."/i", $string)) {
    echo "A match was found.";
} else {
    echo "A match was not found.";
}
?>

I need a similar code that finds special characters like <?, <?php, or ?> in the string. Any suggestions?

You can use same code. Just make sure to escape regex special characters when using them in matching. The question mark must be escaped so your $searchfor becomes <\?php

Using strpos (or stripos) will be faster than using RegEx'es...

if(false === strpos($text, '<?'))
  echo 'Match was not found';
else
  echo 'Match was found';