Is there a function in google sheets that will return only the unique characters in a string?

Question

Is there a function in google sheets that will return only the unique characters in a string?

for example if I input "RRRWWWGGRWG"

it will return "RWG"

Answer 1

Or you can use Mid and Sequence:

=ArrayFormula(join(,unique(mid(A1,sequence(len(A1)),1))))

Answer 2

sure, try:

=JOIN(, UNIQUE(TRANSPOSE(REGEXEXTRACT(A2, REPT("(.)", LEN(A2))))))