Topic summary
Lookup
Extracted from the Wikipedia article Lookup table.
History
Lookup tables were one of the earliest functionalities implemented in computer spreadsheets, with the initial version of VisiCalc (1979) including a LOOKUP function among its original 20 functions. Microsoft Excel includes multiple specialized lookup functions, with VLOOKUP for vertical lookup (as in a traditional lookup book), HLOOKUP for horizontal lookup, and (since 2019) XLOOKUP for outputting multiple output columns at once.