Ways to call a method with Empty argument list

scala> //#PS:72

scala> //psn > a30 > a30

scala> class MyClass(val myStr:String) {
     |   // Example : A method that has an empty argument List
     |   //           **Round brackets are NOT used
     |   def  firstPrint = println(myStr)
     |   // Example : A method that has an empty argument List
     |   //          **Round brackets are used
     |   def secondPrint():Unit = println(myStr)
     | }
defined class MyClass

scala> 

scala> val obj = new MyClass("This is a demo")
obj: MyClass = MyClass@2b6dbbd1

scala> // Round brackets is not used

scala> obj.firstPrint
This is a demo

scala> // This do not work as we have defined this method

scala> // with no round brackets

scala> obj.firstPrint()
<console>:10: error: Unit does not take parameters
              obj.firstPrint()
                            ^

scala> // Round brackets is NOT used

scala> obj.secondPrint
This is a demo

scala> // Round brackets is used

scala> obj.secondPrint()
This is a demo

Best Practice

It has been a convention to define an Empty argument List method without Brackets, when that method has no side effect(Example "mydata".size)