Delimiter used by .h.cd to join subitems of nested lists. Default is " ".

q)show t:([a:til 3]b:3 3#"abc";c:3 3#1 2 3)
a| b     c
-| -----------
0| "abc" 1 2 3
1| "abc" 1 2 3
2| "abc" 1 2 3

q).h.d
" "
q).h.cd t
"a,b,c"
"0,a b c,1 2 3"
"1,a b c,1 2 3"
"2,a b c,1 2 3"

q).h.d:"*"
q).h.cd t
"a,b,c"
"0,a*b*c,1*2*3"
"1,a*b*c,1*2*3"
"2,a*b*c,1*2*3"