Understanding the ActionScript Language > About data types > Null

 

Null

The null data type has only one value, null. This value means "no value"—that is, a lack of data. The null value can be used in a variety of situations. Here are some examples:

To indicate that a variable has not yet received a value

To indicate that a variable no longer contains a value

As the return value of a function, to indicate that no value was available to be returned by the function

As a parameter to a function, to indicate that a parameter is being omitted