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When I invoke + on 2 I get an Int back, but when its done using explicit method call I get Double instead.
scala> 2+2
res1: Int = 4
scala> 2.+(2)
res2: Double = 4.0
It seems that .+() is invoked on implicit converted Int to Double.
scala> 2.+
<console>:16: error: ambiguous reference to overloaded definition,
both method + in class Double of type (x: Char)Double
and method + in class Double of type (x: Short)Double
match expected type ?
2.+
^
Why is that so ?
473
The ::() operator in Scala is utilized to add an element to the beginning of the List. Method Definition: def ::(x: A): List[A] Return Type: It returns the stated list after adding an element to the beginning of it.
=> is syntactic sugar for creating instances of functions. Recall that every function in scala is an instance of a class. For example, the type Int => String , is equivalent to the type Function1[Int,String] i.e. a function that takes an argument of type Int and returns a String .
There are no ++ or -- operators in Scala (use += or -=) Second, Scala encourages the use of immutable values, and with immutable values you'll have no need for these operators.
In Scala 2.9 and before, 2. is interpreted as 2.0 so the ambiguous dot denotes a float literal. You’d explicitly call the method by using the syntax (2).+(2).
The ambiguous floating point syntax will however be deprecated in 2.10:
scala> 2.+(2)
<console>:1: warning: This lexical syntax is deprecated. From scala 2.11, a dot will only be considered part of a number if it is immediately followed by a digit.
2.+(2)
^
<console>:2: warning: This lexical syntax is deprecated. From scala 2.11, a dot will only be considered part of a number if it is immediately followed by a digit.
2.+(2)
^
<console>:8: warning: This lexical syntax is deprecated. From scala 2.11, a dot will only be considered part of a number if it is immediately followed by a digit.
2.+(2)
^
res1: Double = 4.0
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