ISEMPTY

Declaration

ISEMPTY(var) -> bool

Parameters

var (type: object | string | array | NULL)

Any object, string, or list. It will also accept a lack of value, or NULL, as valid input.

Return Values

bool (type: boolean)

A boolean indicating if var is empty. It will output TRUE if it is empty and FALSE otherwise.

Examples

The first example checks to see if an empty list is empty; that is, if the empty list does not contain any items. It does not:

ISEMPTY([]) -> TRUE

The following example checks to see if a blank string is empty; that is, if the blank string does not contain any characters. It does not:

ISEMPTY("") -> TRUE

The following example checks to see if a list containing a single blank string is empty. This list does not count as empty – it contains an item, even that item is only a single blank string:

ISEMPTY([""]) -> FALSE

The following example checks to see if an object containing no name-value pairs is empty. The complete lack of name-value pairs makes this object empty by definition:

ISEMPTY({}) -> TRUE

The following example checks to see if an object containing a single name-value pair – in which the name and the value are both blank strings – is empty. While the name and value are both blank strings, their existence means that the object contains name-value pair, and thus the object doesn't count as empty:

ISEMPTY({"": ""}) -> FALSE

The last example checks if NULL – the lack of any value – is empty. For the purposes of the ISEMPTY function, lack of any value counts as empty:

ISEMPTY(NULL) -> TRUE

Discussion

The ISEMPTY function can be considered the opposite of the ISNOTEMPTY function: they check for the same thing, but ISNOTEMPTY returns FALSE when ISEMPTY would return TRUE and visa versa.