Kotlin: Top two null-safety tricks

[dvas0004]

• The elvis operator (?:) allows you to assign a "default" value if the variable to the left of the elvis operator is null

• The notation someVariable?.let{ } allows you to take an action (which is defined within "let") only if someVariable is non-null

fun main() {
    // the elvis operator
    val test = null    
    val test2 = test ?: "it was null"  
    println(test2)

    // taking action only if variable is non-null
    // using ?.let
    val isNull = null
    isNull?.let{
        println("Inside let with null - will not be printed")
    }

    val isNotNull = 1
    isNotNull?.let{
        println("Inside let with non-null value of '$it' - will be printed")
    }

}

Output:

it was null
Inside let with non-null value of '1' - will be printed

[dvas0004]

https://kotlinlang.org/docs/reference/null-safety.html