Microsoft Axapta is built on application code written in an advanced programming language called X++. This language is inspired by Java, but has been augmented to deal with the specific chores that are relevant in writing software for the enterprise.

X++ supports many native data types, like integer, real, date etc. However, there are few higher-level data types that are useful for aggregating values of simpler types. The only such types available in X++ are arrays and containers, and even these have their shortcomings: Objects, that are the base of an object oriented language, may not be stored in arrays or containers.

The Microsoft Axapta Foundation Classes remedy this situation. They are general purpose, production quality classes used to aggregate other values. The classes are implemented in C++ in order to achieve the maximum performance. The classes are built using state-of-the-art technology that has been tried and tested in the industry for a long time.

Currently the following classes are implemented: Lists, maps, sets, arrays, and structs.

The Axapta Foundation classes

The Microsoft Axapta foundation classes currently fall in five distinct parts: Sets, maps, lists, arrays and structs.  

Each of the foundation classes are generic in the sense that they work on any Microsoft Axapta type. In order to express this using X++ syntax the special type “any” is used to represent values. A value of type any may assume values of any of the specific X++ types. When objects of any of the foundation classes are instantiated, the types of the constituent elements are given in the constructor, in the form of a value of the enumeration type called (appropriately) types.

Each of  the foundation classes may be used form more complex classes. For instance, a stack may easily be implemented using a list where the elements are always added to the start of the list (which then becomes the top of the stack). The classes may also be extended for whatever purposes the programmer may have in mind, for instance to supply more meaningful names for the types within the application context. Thus, the user may extend the list class to create s list of Customer records, where the operations could be made type safe (accepting only Customer records, not any record).