The IsUnknown()
function checks if value
has no value.
Syntax
IsUnknown(value)
Returns
A boolean value true
if value
has no value.
Parameters
value
the value on which the check is performed.
Note: This function is the opposite of the function IsKnown().
Examples
IsUnknown("") /* false */
IsUnknown(0) /* false */
IsUnknown(1/0) /* true */