Lambda and spill array - Addresses and postal codes

[Phantom1]

Hello friends.
I have a table who has a column of addresses and in another column their corresponding postal codes. I need a dynamic array formula that lives in a single cell and spills out every unique postal code in a row and below each postal code all the addresses associated.
Thanks in advance for any response.

 

[Fluff]

How about

=LET(u,UNIQUE(FILTER(A2:A10000,A2:A10000<>"")),m,MAX(COUNTIFS(A:A,u)),DROP(REDUCE("",u,LAMBDA(x,y,HSTACK(x,VSTACK(y,EXPAND(FILTER(B2:B10000,A2:A10000=y),m,,""))))),,1))

 

[djclements]

One possibility could be:

=LET(
    arr, TRANSPOSE(DROP(GROUPBY(Table1[Postal Code],Table1[Address],HSTACK(LAMBDA(v,TEXTJOIN("|",0,"",v,"")),ROWS),0,0),1)),
    a, CHOOSEROWS(arr,2),
    p, TAKE(arr,1),
    r, TAKE(arr,-1),
    n, MAX(r),
    VSTACK(p,TEXTBEFORE(TEXTAFTER(a&REPT("|",n-r),"|",SEQUENCE(n)),"|"))
)

Adjust the row_fields and values arguments of the GROUPBY function as needed (replace Table1[Postal Code] and Table1[Address] to reflect your actual table/range references).

 

[Phantom1]

The usual suspects again.
Excellent work guys.
Thanks again for sharing your knowledge. Both work just fine and sure better than my attempts.
Cheers!

 

[Fluff]

Glad we could help & thanks for the feedback.