PHP - strpos example

Find the position of the first occurrence of a substring in a string

$string = 'hello world';
$post = strpos($string, 'world'); // $pos = 6
$post = strpos($string, 'o'); // $pos = 4

ignoring anything before the offset

$string = 'hello world';
$post = strpos($string, 'o', 5); // $pos = 7