Is it possible to develop applications in Kotlin effectively without knowing Java?

Yes, it is possible to develop applications effectively in Kotlin without knowing Java. Kotlin is a modern programming language with concise and expressive syntax that allows writing clean and understandable code. Although Kotlin is fully compatible with Java and often used together with Java libraries, basic knowledge of Java is not mandatory to start development.

However, understanding the basics of the JVM platform and the Android ecosystem (if it is about Android development) will be helpful. Many concepts and libraries in Android are originally created for Java, so over time, knowledge of Java can facilitate solving complex tasks and integrating with existing code.

An example of simple Kotlin code for Android:

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val greeting = "Hello, Kotlin!"
        println(greeting)
    }
}