explode string if it contains non-alpha characters

How can I explode a string like "bla_bla" into an array like array('bla', 'bla')?

The delimited _ can also be any character besides numbers 0-9 and开发者_运维技巧 letters A-Z (both upper and lower case).

Use preg_split:

$input = 'bla_bla$bla';
$items = preg_split('/[^a-z0-9]/i', $input);

See it in action.

You can do this with preg_split:

$array = preg_split('/[^[:alnum:]]+/', 'bla_bla');

Try it here: http://codepad.org/587rsJIU