What can you tell about properties, and the get and set methods in Kotlin?

In Kotlin, properties are a concept that combines a field and its accessors (get and set). They are defined using the keywords var (mutable) or val (immutable).

class Example {
    var mutableProperty: String = "Mutable" // Mutable property
    val immutableProperty: Int = 10       // Immutable property
}

A getter (get) is a function that returns the value of a property. By default, Kotlin generates a standard getter that returns the value of the internal field. You can override the getter to perform additional logic.

var customGetter: String = "Hello"
    get() {
        // Additional logic when reading
        println("Reading customGetter")
        return field.uppercase() // Return the modified value
    }

field inside the getter refers to the internal field that stores the property's value.

A setter (set) is a function that sets the value of a property. By default, Kotlin generates a standard setter that assigns the passed value to the internal field. You can override the setter to perform additional logic when assigning.

var customSetter: Int = 0
    set(value) {
        // Additional logic when writing
        if (value >= 0) {
            field = value // Assign the value to the field only if it is non-negative
        } else {
            println("Value must be non-negative")
        }
    }

In the setter, value is an automatic parameter representing the value being assigned to the property.

For properties declared with val, a setter is not generated because they are immutable.

Thus, Kotlin properties provide a more convenient and flexible way to work with data compared to explicitly defining fields and separate get and set methods in Java. They allow encapsulating access logic directly within the property definition.