ISLOGICAL
Definition: ISLOGICAL is a function that returns TRUE if a value is a logical value (TRUE or FALSE), and FALSE if it is not.
Syntax: =ISLOGICAL(value)
Situation: This formula is appropriate when you need to check if a value is a logical value (TRUE or FALSE).
Example: If you want to check if cell A1 contains a logical value, the formula =ISLOGICAL(A1) will return TRUE if it contains a logical value, and FALSE if it does not.