Excel ISLOGICAL Function

The Excel ISLOGICAL function returns TRUE when a cell contains the logical values TRUE or FALSE, and returns FALSE for cells that contain any other value, including empty cells.
- value - The value to test as logical.
The ISLOGICAL function returns TRUE when a cell contains the logical values TRUE or FALSE, and returns FALSE for cells that contain any other value, including empty cells.
The ISLOGICAL function takes one argument, value, which can be a cell reference, a formula, or a hardcoded value. When value is TRUE or FALSE, the ISLOGICAL function will return TRUE. If value is any other value, ISLOGICAL will return FALSE.
Examples
The ISLOGICAL function returns TRUE if value is TRUE or FALSE:
If value is a formula, ISLOGICAL checks the result of the formula:
Note that 1 and 0 (zero) are not evaluated as TRUE and FALSE.
Count logicals
To count cells in a range that contain logicals, you can use the SUMPRODUCT function like this:
=SUMPRODUCT(--ISLOGICAL(range))
The double negative coerces the TRUE and FALSE results from ISLOGICAL into 1s and 0s and SUMPRODUCT sums the result.
Notes
- Only the logical values TRUE and FALSE return TRUE
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