Kotlin Sensible Forged is Superior!

I completely missed this Kotlin superior characteristic in my earlier publish – Full C# to Kotlin Syntax Comparisons.

I got here to concentrate on this sensible solid solely after 8 months of Kotlin growth, and I may need been utilizing it with out figuring out it. The Android Studio IDE takes care of it!

As an instance you have got BaseClass and ChildClass like this.

open class BaseClass
class ChildClass(val worth: Int): BaseClass()

and, you create the ChildClass object and being referenced by the BaseClass

val obj: BaseClass = ChildClass(worth = 7)

To entry the info in ChildClass, you do specific solid under.

val childObj = obj as ChildClass
childObj.worth

However the Kotlin compiler can sensible solid mechanically for you within the following state of affairs:

Instance 1

enjoyable smartCastExample1() {
    val obj: BaseClass = ChildClass(worth = 7)
    
    

    if (obj is ChildClass) {
        
        
        println("Baby worth is ${obj.worth}")

        
        val childObj = obj as ChildClass
        println("Baby worth is ${childObj.worth}")
    }
}

obj on this if scope have to be ChildClass, thus Kotlin compiler sensible casts it

Instance 2

enjoyable smartCastExample2() {
    val obj: BaseClass = ChildClass(worth = 7)
    if (obj !is ChildClass) return

    
    println("Baby worth is ${obj.worth}")
}

obj right here have to be ChildClass because it has been returned if it isn’t.

Instance 3

enjoyable smartCastExample3() 

This obj.worth solely will get evaluated when obj is ChildClass. For those who change obj !is ChildClass to obj is ChildClass, the sensible solid will not work.

Instance 4

enjoyable smartCastExample3() {
    val obj: BaseClass = ChildClass(worth = 7)

    
    if (obj is ChildClass && obj.worth == 7) return
}

Just like instance above, the second verify is simply evaluated when obj is ChildClass. For those who change obj is ChildClass to obj !is ChildClass, the sensible solid will not work.

The instance right here is solid from tremendous kind to subtype. It additionally works for nullable kind to non-nullable kind. See extra instance right here.