There are no actual arrays like that in mSL but see /help Token Identifiers, specifically $gettok().

Example:

Php Code:
//var %x = today is wednesday | var %i = 1 | while (%i <= $numtok(%x,32)) { echo -ag token %i -> $gettok(%x,%i,32) | inc %i }

Quote:
token 1 -> today
token 2 -> is
token 3 -> wednesday



Generally, in mIRC, all texts are tokenized/split by spaces.
So when someone says "today is wednesday" on a channel (/help on TEXT), it'll already be split into $1, $2, and $3, where $1- would be the entire text/all tokens.
Also see /help $1- on that.


So regarding above example, there also is a /tokenize command which is not recommended to use but would work as follows:
Php Code:
//var %x = today is wednesday | tokenize 32 %x | echo -ag $*

Quote:
today
is
wednesday