What key features and capabilities of the Kotlin language can you highlight?

Key features and capabilities of Kotlin:

• Java Compatibility: Kotlin is fully compatible with Java, allowing the use of existing Java libraries and frameworks.
• Conciseness: The language reduces boilerplate code, thanks to smart types, data classes, extension functions.
• Type Safety: Built-in null-safety system prevents NullPointerException errors.
• Functional Programming: Support for lambdas, collections with higher-order functions.
• Coroutines: Convenient handling of asynchronous code and concurrency.

Example of data class and coroutines:

// Data class for data storage
data class User(val name: String, val age: Int)

// Coroutine example
import kotlinx.coroutines.*

fun main() = runBlocking {
    launch {
        delay(1000L)
        println("Hello from coroutine!")
    }
    println("Hello from main")
}