Strict Data Typing Variables

Another new feature in ActionScript 2.0 is strict data typing. Strict data typing is the ability to declare the data type of a variable when that variable is initialized. This helps a great deal in debugging large applications. For instance, if you have a login variable that will hold the user's login name as a string, you do not want it accidentally changing to a number or hexadecimal color by accident later in the code.

In ActionScript 1.0, it was possible to have a variable change data types constantly through an application. This is not good coding practice.