In Kotlin, class constructors can be defined in two ways, as primary and as secondary constructors.
Class constructors
Primary constructors
Kotlin has two ways of declaring a constructor. In the example of the User class, we had a primary constructor. Primary constructors are declared with parentheses after the class name, in the class header.
Specifying the constructor keyword is optional if the constructor doesn't have visibility modifiers or annotations.
Constructors can have parameters, but cannot have any initialization code in them. The Java User class constructor has both parameters and initialization code. Initialization code was needed because the private fields needed to be initialized with values from constructor...
