Containers in AX

In X++, container is one of the primitive types, or value types. container is not a class. A container contains an ordered sequence of primitive values or other containers.

A container can be stored in the database. container is one of the column types that you can select when you use the Application Object Tree (AOT) to add a column to a table.

A container slightly resembles an array, or collections such as the List or Stack classes. However, you can never change the size or content of a container after the containeris created. X++ statements that appear to modify a container are internally building a new container and copying values as necessary. Even an assignment of a container to another container variable creates a new copy of the container. All of this has performance implications.

In the X++ functions that provide access to a container (such as conPeek), the container is 1 based not 0 based. Indexing is 1 based for arrays, and for everything else in X++.