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
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.