sheets

see also docs

make column with unique values from a matrix

=SORT(UNIQUE(FLATTEN(A2:E)))

replace

lower(REGEXREPLACE(REGEXREPLACE( REGEXREPLACE(REGEXREPLACE(Trefwoorden!C2:C; "[–’+=&?|,\.() ""$/':;]"; "-") ;"-+";"-"); "[^a-zA-Z0-9\-]";"");"^-|-$"; ""))

Vlookup with Search Key in Multiple Column Range

https://infoinspired.com/google-docs/spreadsheet/vlookup-find-a-search-key-in-multiple-columns-matrix-in-google-sheets/ (won’t work in Excel)

matrix-to-two-columns

=ArrayFormula(split(flatten(B2:D7&"|"&A2:A7);"|"))

transpose comma separated values in multiple rows to one long list of items

=transpose(split(join(",";D:D);","))

shortcut for new sheet

http://sheets.new

Automatische links in spreadsheet kolom voor elke regel

'place this in the header cell above a column, that way you will still be able to sort the sheet
=ArrayFormula(if(A1:A<>"",hyperlink("https://....."&A1:A,"title:"&A1:A),))