You can also use a for loop with a Kotlin Map (which is similar to a Java HashMap). To define a range for the primitive type we use rangeTo() function. // directly on listOf for (n in listOf(1,2,3)) println(n) // 1.3 creates a range for (n in 1.3) println(n) Using for with Maps. There are built-in implementations of ranges for the integral primitive types, like Int, Long and Char. Ranges, provided by the Kotlin standard library, are a powerful solution for implementing iteration and conditional statements in a natural and safe way. It stores handle to first and last elements of the range and also provides contains(value: T): Booleanand isEmpty(): Boolean functions that check two conditions: if the given value belongs to the range and if the range is empty. An interface from kotlin.ranges package called ClosedRange is a base declaration that models the idea of the range. The idea of a range itself can be seen as an abstract data type that models a closed scope of values or a set of objects that can be iterated through, in a concise way. Let’s get started 🚀! Iterating through primitive types However, there are many more ways through which you can iterate through Range. Next, we are going to implement a custom progression for the LocalDate class. We have given an example to show how can you traverse through Range in Kotlin.

First, we are going to discover built-in range implementations for the integral types like Char, Int or Long.

In this post, we are going to explore how to use range expressions in action. In order to make the syntax for loop iteration and control flow statements safe and natural to read, Kotlin standard library provides a concept of range.

Kotlin for loop range