Question

Explain the difference between the terms Nil, Null, None and Nothing.

Answer 1

Null, null, Nil, Nothing, None, and Unit are all used to represent empty values in Scala.   

1. Null refers to the absence of data, and its type is Null with a capital N.  
2. Null is considered to be a list that contains zero items. Essentially, it indicates the end of the list.  
3. Nothing is also a trait without instances.   
4. None represents a sensible return value. 
5. Unit is the return type for functions that return no value.