how to find a array of occurence of a character in a string

Question

I am searching for a function in PHP to return the array of position of a character in a string.

Inputing those parameters "hello world", 'o' would return (4,7).

Thanks in advance.

Answer 1

No looping needed

$str = 'Hello World';
$letter='o';
$letterPositions = array_keys(array_intersect(str_split($str),array($letter)));

var_dump($letterPositions);

Answer 2

you can check this http://www.php.net/manual/en/function.strpos.php#92849 or http://www.php.net/manual/en/function.strpos.php#87061, there are custom strpos functions to find all occurrences