How to check constructor arguments and throw an exception or make an assertion in a default constructor in Scala?

Question

I would like to check constructor arguments and refuse to construct throwing IllegalArgumentException in case the arguments set is not valid (the values don\'t

Answer 1

scala> class Foo(arg: Int) {
     |   require (arg == 0)
     | }
defined class Foo

scala> new Foo(0)
res24: Foo = Foo@61ecb73c

scala> new Foo(1)
java.lang.IllegalArgumentException: requirement failed