How to use the Kotlin MCQ Quiz
- 1. Choose the length10 random Kotlin questions, or all 25. Untick shuffle for a fixed order.
- 2. AnswerPick an option and see straight away whether it's right, with a one-line reason.
- 3. See your scoreFinish to get your score and a review of every question with the correct answer.
What the quiz covers
Kotlin is the preferred language for Android, so this quiz focuses on the features Android interviews ask about most. The 25 questions are grouped into 10 areas, shown above each question: Basics, Null safety, Classes, Control flow, Functions, Scope functions, Collections, Coroutines, Properties, Types.
A sample question explained
"What does the Elvis operator ?: do?" The answer is Returns the right side if the left is null. val n = name ?: "Guest". Combine it with safe calls: user?.name ?: "Guest" is idiomatic Kotlin you'll write every day.
More questions you'll meet
A few of the other Kotlin questions in the bank:
- What does the safe call operator ?. do?
- What does a data class generate automatically?
- Kotlin classes are by default
- What does 1..5 create?
- What is an extension function?
- listOf(1, 2, 3) returns
- What is a suspend function?
Study tips
- Try each question in the Kotlin Playground in your browser.
- Practise the five scope functions until you can say which returns what.
- Aim for at least 20 out of 25 on two separate attempts before you treat Kotlin as revised; one lucky score can hide gaps.
Questions and options are shuffled on each attempt, so a retake is a fresh test. The Kotlin questions were written by Uncodemy for practice; they aren't copied from any exam or company test.
Frequently asked questions
Do I need Java first?
No, but knowing Java helps because Kotlin runs on the JVM and interoperates with it.
Are Compose questions included?
No. See the Android development quiz for Android-specific topics.
Is the Kotlin MCQ quiz free?
Yes. Every question in the Kotlin MCQ quiz can be answered without signing up. When you finish your first round, we ask once for your name and WhatsApp number to show your score; after that the Kotlin MCQ quiz and every other Uncodemy tool open straight away.