Exploring the use of range expressions to iterate through alphabet characters

Ranges, provided by the Kotlin standard library, are a powerful solution for implementing iteration and conditional statements in a natural and safe way. A range can be understood as an abstract data type that represents a set of iterable elements and allows iteration through them in a declarative way. The ClosedRange interface from the kotlin.ranges package is a basic model of the range data structure. It contains references to the first and last elements of the range and provides the contains(value: T): Boolean and isEmpty(): Boolean functions, which are responsible for checking whether the specified element belongs to the range and whether the range is empty. In this recipe, we are going to learn how to declare a range that consists of alphabet characters and iterate through it in a decreasing order.