When a cell contains a formula ISFORMULA will return TRUE regardless of the formula’s output or error conditions.
The ISFORMULA takes oneargument,reference, which must be a cell reference.
you could use FORMULATEXT to extract the formula as text from a cell.
If you use FORMULATEXT on a cell that doesn’t contain a formula, it returns #N/A.
For example, if A1 contains “apple”, ISBLANK(A1) returns FALSE.
ISEVEN will return the #VALUE error if a value is not numeric.
ISNONTEXT Function
The Excel ISNONTEXT function returns TRUE when a cell contains any value except text.
This includes numbers, dates, times, errors, and formulas that do not return text.
ISNONTEXT also returns TRUE when a cell is empty.
ISODD will return the #VALUE error if a value is not numeric.
ISREF Function
The Excel ISREF returns TRUE when a cell contains a reference and FALSE if not.
you’re free to use the ISREF function to check for a reference in a formula.
