Mastering Kotlin Essentials/

...

/

Extension Functions and Properties

Extension Functions and Properties

Explore Kotlin’s extension functions and properties, gaining insights into their working.

We'll cover the following...

Extension functions

Let’s examine the Java bytecode generated from a Kotlin extension function:

Press + to interact
fun String.remove(value: String) = this.replace(value, "")
fun main() {
    println("A B C".remove(" ")) // ABC
}

As a result, we should see the following code:

Press + to interact
final class PlaygroundKt {
    public static final String remove(
            String $this$remove,
            String value
    ) {
        // Null-check using a conditional operator
        $this$remove = ($this$remove != null) ? $this$remove : "";
        value = (value != null) ? value : "";
        // Use standard Java replace method
        return $this$remove.replace(value, "");
    }
    public static void main(String[] args) {
        // parameter not-null check
        String var1 = remove("A B C", " ");
        System.out.println(var1);
    }
}

Notice ...