SUM of VLOOKUP*ARRAY gives different answer when used as single cell

[the Core]

Hi all,

How can I get the result of this multi cell array formula in a single cell?

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That formula gives different results when used as either single cell or multi cell. To discuss the formula I abbreviate it like this:

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The result of a single cell is that the first value returned by the VLOOKUP (V) is multiplied with the sum or the ARRAY (A). The result I want is what you get when you run the formula in multiple cells: it multiplies the first value returned by V with the first value of A, the second with the second, and so forth. In short:
Single cell result: V1 * SUM(A)
multi cell result: V1*A1 + V2*A2 + V3*A3

Example:
data (A2:B5)

atom	mass
hydrogen	1
carbon	12
oxygen	16
chlorine	35

molecule (A8:B10)

atom	amount
carbon	2
hydrogen	6
oxygen	1

Use the given formula in any single cell and it will display 108 (9 x 12). Select two or more cells before entering this formula with [ctrl + shift + enter] and it gives 46. That is what I want.

Cor

[XOR LX]

Hi,

The required single-cell array formula using VLOOKUP requires a little coercion:

=SUM(VLOOKUP(T(IF({1},$A$8:$A$10)),$A$2:$B$5,2,0)*$B$8:$B$10)

More appropriate is the simple:

=SUM(SUMIF($A$2:$B$5,$A$8:$A$10,$B$2:$B$5)*$B$8:$B$10)

again with CSE, or:

=SUMPRODUCT(SUMIF($A$2:$B$5,$A$8:$A$10,$B$2:$B$5)*$B$8:$B$10)

without CSE.

Regards

[Glenn Kennedy]

Try this array formula:

=SUMPRODUCT(--($A$8:$A$10=TRANSPOSE($A$2:$A$5))*$B$8:$B$10*TRANSPOSE($B$2:$B$5))

You may need ; instead of ,

Array Formulae are a little different from ordinary formulae in that they MUST be confirmed in the FIRST CELL ONLY by pressing CTRL+SHIFT+ENTER to activate the array, not just ENTER. After that, the array can be dragged down as normal, to cover the desired range.

You will know the array is active when you see curly brackets { } - or "curly braces" for those of you in the USA, or "flower brackets" for those of you in India - appear around the outside of your formula. If you do not use CTRL+SHIFT+ENTER you will (almost always) get an error message or an incorrect answer. Press F2 on that cell and try again.

Don't type the curly brackets yourself - it won't work...

[Glenn Kennedy]

Go with XOR LX's 3rd solution, not mine!!

[the Core]

Wow, such a fast reply. Thank you so much XOR LX and Glenn!

All three of your suggestions work, also in the real sheet I'm using.
So, it seems in my formula the search values had to be converted to text values using an IF statement (didn't work without that).
I couldn't have guessed, thanks! I'll be using the last formula given by XOR.

[Glenn Kennedy]

Wise decision!!

You're welcome.

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