Why == operator and equals() behave differently for values of AnyVal in Scala

Question

In the scaladoc of scala.Any, the operator == (or, method ==) is explained:

The expression x == that

Answer 1

I expect this was done because of auto-boxing and a desire to stay consistent with expectations held over from Java, and maths in generel (1 = 1.0 = 1 (represented as a long) etc.). For example, running comparisons between Scala numeric types and Java numeric types:

scala> val foo: Long = 3L
foo: Long = 3

scala> val bar: Int = 3
bar: Int = 3

scala> foo == bar
res0: Boolean = true

scala> foo.equals(bar)
res1: Boolean = false

Compared with:

scala> val jfoo = new java.lang.Long(3L)
jfoo: Long = 3

scala> val jbar = new java.lang.Integer(3)
jbar: Integer = 3

scala> jfoo == jbar
res2: Boolean = true

scala> jfoo.equals(jbar)
res3: Boolean = false