Hands-On Object-Oriented Programming with Kotlin

The filterNotNull function

The filterNotNull function ignores all null values and returns a new list without null elements. Let's create a list of different data types, including null values, and then apply the filterNotNull() function:

val list = listOf("One", 2, 3, null, "Four", null)var newList = list.filterNotNull()println(newList)

The output of the list is as follows:

[One, 2, 3, Four]

The filterNotNull function can be used instead of the listOfNotNull function, which is used to create a list of non-null elements:

var notNullList =  listOfNotNull(1,2,null,"Three","Four")println("Not null $notNullList")

Here, any null value that is inserted is ignored.