The for loop

Learn to write counted loops with for.

The for loop runs a block multiple times. In Kotlin, for iterates over a range or a collection.

for (i in 1..5) {
    println(i)
}

This runs the block for each value of i from 1 to 5 (5 inclusive), printing 1, 2, 3, 4, 5. 1..5 is a range; you'll see it in detail later.

i is the loop variable and takes the next value each step. The loop ends when the range is exhausted.

for over a collection

for can also iterate over the items of a collection (for example, a list).

val fruits = listOf("apple", "pear", "cherry")
for (fruit in fruits) {
    println(fruit)
}

Here fruit takes one item from the list each step: first "apple", then "pear", then "cherry". You'll learn listOf later.

You don't need to write the loop variable's type; Kotlin infers it.

Write a fun main(). Use a for (i in 1..5) loop to call println(i). The output should be 1, 2, 3, 4, 5, each on its own line.

Show example solution

fun main() {
    for (i in 1..5) {
        println(i)
    }
}

Complete the for range

for (i in 1____5) { println(i) }

Show answer

for (i in 1..5) { println(i) }