Scala companion class warning

Question

I am new to Scala programming, can someone explain me below warning reason?

I trie

Answer 1

This is specific to the REPL (Read Evaluate Print Loop), since it can't know when user input ends.

Use :paste to get around it :

scala> class A {}
defined class A

scala> object A {}
defined object A
warning: previously defined class A is not a companion to object A.
Companions must be defined together; you may wish to use :paste mode for this.

scala> :paste
// Entering paste mode (ctrl-D to finish)

class A {}
object A {}

// Exiting paste mode, now interpreting.

defined class A
defined object A