New Functionality In Microsoft Dynamics 365 Business Central 2025 Wave 1: Create Lists and Dictionaries of Interfaces in AL

This post is part of the New Functionality In Microsoft Dynamics 365 Business Central 2025 Wave 1 series in which I am taking a look at the new functionality introduced in Microsoft Dynamics 365 Business Central 2025 Wave 1.

The 18th of the new functionality in the Development section is create lists and dictionaries of interfaces in AL.

In the Business Central AL language, dictionaries and lists are powerful data structures that offer efficient lookup of key-value pairs and ordered collections, and both allowing managing collections of data dynamically. Microsoft are now adding the ability to have lists and dictionaries of interfaces, providing more flexibility and power when you work with interface abstractions.

Enabled for: Admins, makers, marketers, or analysts, automatically
Public Preview: Apr 2025
General Availability: Apr 2025

Feature Details

You can now create lists or dictionaries of interfaces.

The syntax follows these patterns, aligned with creating a List or Dictionary of a simple type:

• List of [Interface IFoo]
• Dictionary of [; Interface IFoo]

In the System Application, you can find the complete examples of using a list of interfaces in the Telemetry Logger.

The following examples illustrate creating lists and dictionaries with interfaces.