Kotlin test

The Kotlin test evaluates candidates' understanding of Kotlin, a modern programming language used for Android app development and other general-purpose applications. The test begins by assessing basic syntax and the structure of Kotlin programs, including how to declare variables and constants using `val` and `var`, and understanding the difference between mutable and immutable variables. Candidates should be familiar with Kotlin’s strong typing system, including nullable types and the safe call operator `?.`.

Kotlin’s control flow mechanisms, including `if`, `when`, and `for` loops, are examined to determine the candidate’s ability to control logic flow efficiently in Kotlin programs. Functions are another key area, with questions on how to declare and use functions in Kotlin, including default parameters, named arguments, and higher-order functions. Candidates should also be able to demonstrate knowledge of Kotlin’s support for functional programming paradigms, including lambda expressions and the use of the `map`, `filter`, and `reduce` functions on collections.

Object-oriented programming (OOP) concepts are tested, with questions covering classes, inheritance, interfaces, and abstract classes. Understanding Kotlin’s powerful null safety system is a major part of the test, with candidates expected to use safe calls, elvis operators, and the `!!` operator correctly. A strong grasp of Kotlin-specific features such as extension functions, data classes, and sealed classes is also important.

The test also touches on Kotlin’s asynchronous programming features, especially coroutines, which are used for managing concurrent tasks. The candidate’s understanding of Kotlin’s interoperability with Java is assessed, including how Kotlin can be used in Java-based projects. The test evaluates how well candidates can write concise, readable, and efficient Kotlin code.

Additionally, knowledge of testing and debugging Kotlin code, including using unit tests and debugging tools, is included in the assessment.