PHP strlen() function

The strlen() function returns the length of a string, in characters.

The example below returns the length of the string "Hello world!":

Code:
<?php
echo strlen("Hello world!");
?>

PHP strpos() function

The strpos() function is used to search for a specified character or text within a string.

If a match is found, it will return the character position of the first match. If no match is found, it will return FALSE.

The example below searches for the text "world" in the string "Hello world!":

Code:
<?php
echo strpos("Hello world!","world");
?>