The Switch function argument list consists of pairs of expressions and values. The expressions are evaluated from left to right, and the value associated with the first expression to evaluate to True is returned. If the parts aren't properly paired, a run-time error occurs. Switch evaluates all of the expressions, even though it returns only one of them. Switch returns Null in two cases: if none of the expressions is true, or if the first True expression has a corresponding value that is Null.
expression1, expression2, expression_n is a list of expressions you want to evaluate.
value1, value2, ... value_n is a list of values to be returned if the corresponding expression is True.