method created with this() in header

Question

If a method is created like below what is the result of :this() at the end? why can it be needed? public Product(int new_id short product_name string product_type) : this() Thanks

Vulpes · Answer

That's an example of 'constructor chaining'. The Product class contains (at least) two constructors. One takes three arguments (an int short and a string) and the other takes no arguments. When the constructor which takes 3 arguments is invoked the first thing it does is to call the constructor which takes no arguments - this is what :this() does. The body of the constructor then executes normally. Constructor chaining therefore avoids having to duplicate code.