IfThen is a conditional function that returns a value when the condition equals True, and another value when the condition equals False.
IfThen(Condition, TrueParameter, FalseParameter)
Condition is a logical expression that evaluates to true or false. Full conditional logic can be used as well as complex Boolean operators (And, Not, and Or). A condition can also test for #missing and #error values.
TrueParameter and FalseParameter are expressions that are evaluated based on the outcome of the condition.