The "double unary minus" converts a logical (TRUE or FALSE) value to a
number (1 or 0).
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David Biddulph

"Jan T." wrote in message
...
Thank you very much for helping.
But can you tell me, what does the two minus before (--ISNUMBER... do?

Jan

"Teethless mama" skrev i melding
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=SUMPRODUCT(--ISNUMBER(SEARCH("K",A1:F1)))