In Scala, is assignment operator “=” a method call?

Question

As per Scala book, \"Programming In Scala\" -

Scala is an object-oriented language in pure form: every value is an object and every operation is a method call

Answer 1

A little addition to Jatin answer. There is one case when = can be considered as a method call, but actually it's just a syntactic sugar. In OO part of Scala, where ugly vars lives, you can write the following:

class Test { 
  private var x0: Int = 0
  def x = x0
  def x_=(a: Int) = x0 = a 
}

Then you can assign new ints to x:

scala> val t = new Test
t: Test = Test@4166d6d3

scala> t.x = 1
t.x: Int = 1

The last line will be desugared into t.x_=(1). I think in this case, considering syntactic sugar, it's possible to say that = is a method call.

Answer 2

While the other answers are correct for standard Scala, there is a variant called Scala-Virtualized where = and other control structures are method calls.

Answer 3

Nope. Assignment operator (=) is a reserved word. Also the below are:

_ : = => <- <: <% >: # @

For a more comprehensive list refer § 1.1. Some more information regarding = is described in § 6.12.4.

So yes it is not a method call.