Uses an index to return a value from a list of up to 30 values.
CHOOSE(Index; Value1; ...; Value30)
Index is a reference or number between 1 and 30 indicating which value is to be taken from the list.
Value1, Value2, ..., Value30 is the list of values entered as a reference to a cell or as individual values.
=CHOOSE(A1;B1;B2;B3;"Today";"Yesterday";"Tomorrow"), for example, returns the contents of cell B2 for A1 = 2; for A1 = 4, the function returns the text "Today".