What is the primary role of a class constructor in ABAP?

The primary role of a class constructor in ABAP is to initialize class attributes and state. When a new instance of a class is created, the constructor method is automatically executed, which allows developers to set initial values for the instance attributes and perform any necessary setup for the object's state. This ensures that every new object begins with a defined state, which is critical for maintaining data integrity and functionality throughout the lifecycle of the instance.

In contrast, defining the class interface focuses on specifying what methods and properties are accessible, rather than on instantiating or initializing those properties. Creating locked instances does not pertain solely to the constructor, as locking mechanisms are typically used for controlling access in concurrency scenarios. Inheriting class properties involves structure and design of classes in a way that allows one class to gain attributes and methods from another, which is a different aspect of object-oriented programming than initialization. Thus, the role of the class constructor centers squarely on ensuring that class attributes have their required initial values and that the object is in a valid state upon instantiation.