For loop with step and downTo in Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the downTo keyword do in a Kotlin for loop?

It creates a range that counts backwards from a higher number down to a lower number.

beginner

How do you make a Kotlin for loop skip numbers when counting?

Use the step keyword to specify how many numbers to skip each time.

intermediate

Write a Kotlin for loop that counts down from 10 to 1, stepping by 2.

for (i in 10 downTo 1 step 2) { println(i) }

intermediate

What will this Kotlin code print?

for (i in 5 downTo 1 step 2) {
    println(i)
}

It will print: 5 3 1 Because it counts down from 5 to 1, skipping every second number.

beginner

Can you use step with a normal increasing range in Kotlin?

Yes! For example, for (i in 1..10 step 3) counts from 1 to 10, jumping 3 numbers each time.

What does for (i in 10 downTo 1 step 3) do?

A Counts up from 10 to 1, jumping 3 numbers each time

B Counts up from 1 to 10, jumping 3 numbers each time

C Counts down from 1 to 10, jumping 3 numbers each time

D Counts down from 10 to 1, jumping 3 numbers each time

The downTo keyword makes the loop count backwards, and step 3 makes it jump 3 numbers each time.

Which keyword lets you skip numbers in a Kotlin for loop?

A skip

B jump

C step

D downTo

step controls how many numbers the loop skips each time.

What will for (i in 1..5 step 2) print?

A 1 2 3 4 5

B 1 3 5

C 5 3 1

D 2 4

It counts up from 1 to 5, stepping by 2, so it prints 1, 3, and 5.

What is the output of this code?

for (i in 3 downTo 1) {
 println(i)
}

A 3 2 1

B Error

C 1 3

D 1 2 3

The loop counts down from 3 to 1, printing 3, then 2, then 1.

Can step be used with downTo in Kotlin?

A Yes, it works with both increasing and decreasing ranges

B No, only with increasing ranges

C Only with <code>until</code>

D Only with <code>rangeTo</code>

step works with both downTo (decreasing) and normal increasing ranges.

Explain how to use downTo and step together in a Kotlin for loop.

Think about counting backwards and skipping numbers.

Describe what happens when you use step in a Kotlin for loop with an increasing range.

Imagine counting forward but only saying every other number.