If Scala's == calls equals, why doesn't this throw an exception?

Question

scala> val x:String = null
x: String = null

scala> x == "Hey"
res0: Boolean = false

This should translate to x.equals("Hey")?

Because `==` is not equal to `equals`, see: http://stackoverflow.com/questions/7681161/whats-the-difference-between-and-equals-in-scala — kiritsuku, Nov 09 '15 at 15:25

score 3 · Accepted Answer · answered Nov 09 '15 at 16:43

As per the SLS:

6.3 The Null Value

The null value is of type scala.Null, and is thus compatible with every reference type. It denotes a reference value which refers to a special “null” object. This object implements methods in class scala.AnyRef as follows:

• eq(x ) and ==(x ) return true iff the argument x is also the “null” object.

• ne(x ) and !=(x ) return true iff the argument x is not also the “null” object.

• isInstanceOf[T ] always returns false.

• asInstanceOf[T ] returns the default value (see §4.2) of type T .

• ## returns “0”. A reference to any other member of the “null” object causes a NullPointerException to be thrown.

If Scala's == calls equals, why doesn't this throw an exception?

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