Split string on a space before one of two whitelisted words

I have strings like this:

wh4tever_(h4r4ct3rs +syMb0|s! ASC
wh4tever_(h4r4ct3rs +syMb0|s! DESC

I don't know what the first characters are, but I know that they end by ' ASC' or ' DESC', and I want to split them so that I get an array like:

array(
    [0] => 'wh4tever_(h4r4ct3rs +syMb0|s!'
    [1] => 'ASC' //or 'DESC'
)

I know it must be absolutely easy using preg_split(), but regexps are something I assumed I'll never get on well with...

You can use the following regular expression with preg_split():

\s(?=(ASC|DESC))

Explanation:

• \s - match any whitespace character
• (?= - start of positive lookahead
  • (ASC|DESC) - ASC or DESC
• ) - end of positive lookahead

Visualization:

Complete:

$str = 'wh4tever_(h4r4ct3rs +syMb0|s! ASC';
$arr = preg_split('/\s(?=(ASC|DESC))/', $str);
print_r($arr);

Output:

Array
(
    [0] => wh4tever_(h4r4ct3rs +syMb0|s!
    [1] => ASC
)

Demo