If class A extends class B, the constructor of class B (the parent class) will be called first when an object of class A is created. This is because the child class (A) relies on the initialization of its parent class (B) before it can be fully constructed. Why? Java ensures that the parent class's properties and methods are initialized before the child class. The first statement in a child class's constructor is an implicit or explicit call to the parent class's constructor using super().