strpos function

mixed strpos (string $haystack,mixed $needle [, int $offset = 0])

find the numeric position of the first occurrence of needle in the haystack string.

Parameters:

=> haystack: The string that is searched
=> needle :it is not a string.it is converted to an integer and applied as the ordinal value of a character.
=>offset: if specified,search will start this number of characters counted from the beginning of the string.offset is not negative.   
 

<?php
$string= 'abc';$find   = 'a';$pos = strpos($string, $find  );
// Note our use of ===.  Simply == would not work as expected
// because the position of 'a' was the 0th (first) character.if ($pos === false) {
    echo "The string '$find' was not found in the string '$string'";
} else {
    echo "The string '$find' was found in the string '$string'";
    echo " and exists at position $pos";
}?>