Question re previous post about counting uniques

[kweaver]

I saw Fluff's solution. I had a different approach. However, I'm curious why you can't replace F2# in E2 with the code in F2:

FILTER(UNIQUE($A$2:$B$10),{1,0})

Book2
	A	B	C	D	E	F
1	GL	Contract	Rand. Id
2	GL1	Contract 1	text	GL1	2	GL1
3	GL1	Contract 1	text	GL2	1	GL1
4	GL1	Contract 2	text	GL3	3	GL2
5	GL2	Contract 3	text			GL3
6	GL2	Contract 3	text			GL3
7	GL2	Contract 3	text			GL3
8	GL3	Contract 4	text
9	GL3	Contract 5	text
10	GL3	Contract 6	text
Sheet2

Cell Formulas
Range	Formula
D2:D4	D2	=UNIQUE(A2:A10)
E2:E4	E2	=COUNTIF(F2#,D2#)
F2:F7	F2	=FILTER(UNIQUE($A$2:$B$10),{1,0})
Dynamic array formulas.

 

[jasonb75]

Countif requires a range for the first argument, the formula in F2 returns an array, not a range.