Can large brackets be referred to cells in a SUMPRODUCT formula?

[billj]

Hi, everyone, large brackets can be applied in a SUMPRODUCT formula like:

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But the formula below will fail:

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I can certainly expand the formula to:

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But if I have too many keywords C1, C2, ... C100, then it is a burn to write a long formula like the above.

Is there a way to write a concise formula accommodate all these C1, C2, ... C100?

[tim201110]

=sumproduct(--not(isna(match(c1:c100,a1:a100,))),b1:b100)

[billj]

Thank you, tim201110. It works perfectly. Thank you so much.