Explain the null safety in Kotlin

Null Safety in Kotlin

Kotlin's null safety is a set of features designed to help developers avoid the dreaded NullPointerException (NPE) that often plagues Java programs. In Kotlin, variables are non-nullable by default, meaning they cannot hold a null value unless explicitly declared as nullable.

Here are the key aspects of null safety in Kotlin:

Nullable Types

To declare a variable as nullable, you append a ? to the type, like this:

var name: String? = null

Now, name can hold either a String value or null.

Safe Call Operator (?.)

The safe call operator allows you to safely access properties or call methods on a nullable reference without causing an NPE. If the reference is null, the expression returns null instead of throwing an exception.

val length = name?.length

Here, length will be null if name is null.

Elvis Operator (?:)

The Elvis operator provides a concise way to handle nullable values...