The value to check.
true if the value is considered "not defined"; otherwise, false.
IsNotDefined(null); // true
IsNotDefined(undefined); // true
IsNotDefined(NaN); // true
IsNotDefined(''); // false
IsNotDefined(' '); // false
IsNotDefined([]); // false
IsNotDefined({}); // false
IsNotDefined(0); // false
IsNotDefined(false); // false
IsNotDefined('hello'); // false
IsNotDefined([1, 2]); // false
IsNotDefined({ key: 'value' }); // false
Checks whether a given value is "not defined" in a broad sense.
A value is considered "not defined" if it meets any of the following criteria:
null: The value is explicitly null.undefined: The value has not been assigned.NaN: The value is Not-a-Number (only applies to numbers).