Pattern match for variable in scope (Scala)

Question

In the following code

val x = 5
val y = 4 match {
  case x => true
  case _ => false
}

the value y is true. Scala interp

Answer 1

Backticking the variable indicates to bind a scoped variable:

val x = 5
val y = 4 match { case `x` => true; case _ => false }

returns false.

Alternatively, if a variable starts with an uppercase letter, it binds to a scoped variable without backticking.

Answer 2

Invoking the least astonishment principle, I will simply do:

val x = 5
val y = 4 match {
  case z if z == x => true
  case _ => false
}