Dynamics 365 Business Central and AL language contain many built-in functions that you as a developer can use during your development projects.

These built-in functions, called interaction functions, can help you interact with the user, show a message, or request confirmations.

This module will explain how to use functions to work with string values, numeric values, and dates. Also, built-in functions for arrays and lists will be discussed.

You can convert a text data type into a code data type and an integer into a decimal data type, but you can't convert an integer into text or text into a decimal. Therefore, you'll also learn about some variable functions like Format and Evaluate.

Numerous system functions can help you identify a user, a company, today's date, or a time that can be used when you are coding.