Hands-On Object-Oriented Programming with Kotlin

Dynamic binding

Runtime polymorphism, which is also known as late or dynamic binding, is used to determine which function to invoke at runtime. When a variable of a superclass is initialized with the object of a child class and the child class provides its own function definition by overriding it, a compiler cannot predict which object type it is and which function should be called. This is also difficult when a list of different shapes is assigned to the shapes list variable:

val shapes : MutableList<Shape> = mutableListOf(triangle,circle)for (shape in shapes){      shape.draw() }

When a compiler can't resolve the binding at compile time, this is decided later when the program executes. This technique is called late binding or dynamic binding. ...