Backing Field

Use field inside a setter to store a normalized value.

BackingField.kt

class Label {
    var text: String = "ready"
        set(value) {
            field = value.trim()
        }
}

fun main() {
    val raw = 
    val label = Label()
    label.text = raw
    val clean = label.text

    println("clean=$clean")
    println("length=${clean.length}")
}

class Label {
    var text: String = "ready"
        set(value) {
            field = value.trim()
        }
}

fun main() {
    val raw = 
    val label = Label()
    label.text = raw
    val clean = label.text

    println("clean=$clean")
    println("length=${clean.length}")
}

class Label {
    var text: String = "ready"
        set(value) {
            field = value.trim()
        }
}

fun main() {
    val raw = 
    val label = Label()
    label.text = raw
    val clean = label.text

    println("clean=$clean")
    println("length=${clean.length}")
}

field Inside a custom accessor, `field` refers to the property's backing storage.