.Q.ty x

Where x is a list, returns the type of x as a character code:

q)t:([]a:3 4 5;b:"abc";c:(3;"xy";`ab);d:3 2#3 4 5;e:("abc";"de";"fg"))
q)t
a b c    d   e
------------------
3 a 3    3 4 "abc"
4 b "xy" 5 3 "de"
5 c `ab  4 5 "fg"
q).Q.ty each t`a`b`c`d`e
"jc JC"