Careeroza

apply

Configure and Return the Object

apply returns the object itself, so it is perfect for setting up a new object: "create this, and apply these settings".

Example

class Notification {
    var title = ""
    var body = ""
    var priority = "normal"
    var channel = "general"
    override fun toString() = "[$channel/$priority] $title - $body"
}

fun main() {
    val n = Notification().apply {
        title = "Flash Sale"
        body = "Up to 70% off on electronics"
        priority = "high"
    }
    println(n)

    val list = mutableListOf<String>().apply {
        add("Wi-Fi")
        add("AC")
        addAll(listOf("Breakfast", "Parking"))
    }
    println(list)
}

Output

[general/high] Flash Sale - Up to 70% off on electronics
[Wi-Fi, AC, Breakfast, Parking]