Safe Calls and Elvis Operator

fun main(args : Array<String>){
   


}

fun ifElseNull(){
 //safe call operator ?.
val text: String? = null
val textLength = if (text != null) text.length else 7
println(textLength)
    
}

 //elvis operator ?:
 fun elvisOperator(){
     val text: String? = "okkk"
     val textLength = text?.length ?: 7
 }
 
// non-null assertion
fun nonNullAssert(){
    val text: String? = null
    //null pointer exeption
    val textLength = text!!.length
    println(textLength)
}