Kotlin For Loop

Often when you work with arrays, you need to loop through all of the elements.

To loop through array elements, use the for loop together with the in operator:

Output all elements in the cars array:

val cars = arrayOf("Volvo", "BMW", "Ford", "Mazda")
for (x in cars) {
  println(x)
}

You can loop through all kinds of arrays. In the example above, we used an array of strings.

In the example below, we loop through an array of integers:

val nums = arrayOf(1, 5, 10, 15, 20)
for (x in nums) {
  println(x)
}

Traditional For Loop

Unlike Java and other programming languages, there is no traditional for loop in Kotlin.

In Kotlin, the for loop is used to loop through arrays, ranges, and other things that contains a countable number of values.

You will learn more about ranges in the next chapter - which will create a range of values.