(PHP 5)
strpbrk — Search a string for any of a set of characters
$haystack
   , string $char_list
   )
   strpbrk() searches the haystack
   string for a char_list.
  
haystack
       The string where char_list is looked for.
      
char_listThis parameter is case sensitive.
   Returns a string starting from the character found, or FALSE if it is
   not found.
  
Example #1 strpbrk() example
<?php
$text = 'This is a Simple text.';
// this echoes "is is a Simple text." because 'i' is matched first
echo strpbrk($text, 'mi');
// this echoes "Simple text." because chars are case sensitive
echo strpbrk($text, 'S');
?>